Logining to AspNet Zero Website and get Access Token for api request via RestSharp

AbpAjaxResponse

public class AjaxResponse<TResult> : AjaxResponseBase
    {
        /// <summary>
        /// The actual result object of AJAX request.
        /// It is set if <see cref="AjaxResponseBase.Success"/> is true.
        /// </summary>
        public TResult Result { get; set; }

        /// <summary>
        /// Creates an <see cref="AjaxResponse"/> object with <see cref="Result"/> specified.
        /// <see cref="AjaxResponseBase.Success"/> is set as true.
        /// </summary>
        /// <param name="result">The actual result object of AJAX request</param>
        public AjaxResponse(TResult result)
        {
            Result = result;
            Success = true;
        }

        /// <summary>
        /// Creates an <see cref="AjaxResponse"/> object.
        /// <see cref="AjaxResponseBase.Success"/> is set as true.
        /// </summary>
        public AjaxResponse()
        {
            Success = true;
        }

        /// <summary>
        /// Creates an <see cref="AjaxResponse"/> object with <see cref="AjaxResponseBase.Success"/> specified.
        /// </summary>
        /// <param name="success">Indicates success status of the result</param>
        public AjaxResponse(bool success)
        {
            Success = success;
        }

        /// <summary>
        /// Creates an <see cref="AjaxResponse"/> object with <see cref="AjaxResponseBase.Error"/> specified.
        /// <see cref="AjaxResponseBase.Success"/> is set as false.
        /// </summary>
        /// <param name="error">Error details</param>
        /// <param name="unAuthorizedRequest">Used to indicate that the current user has no privilege to perform this request</param>
        public AjaxResponse(ErrorInfo error, bool unAuthorizedRequest = false)
        {
            Error = error;
            UnAuthorizedRequest = unAuthorizedRequest;
            Success = false;
        }
    }

AjaxResponseBase.cs

  public abstract class AjaxResponseBase
    {
        /// <summary>
        /// This property can be used to redirect user to a specified URL.
        /// </summary>
        public string TargetUrl { get; set; }

        /// <summary>
        /// Indicates success status of the result.
        /// Set <see cref="Error"/> if this value is false.
        /// </summary>
        public bool Success { get; set; }

        /// <summary>
        /// Error details (Must and only set if <see cref="Success"/> is false).
        /// </summary>
        public ErrorInfo Error { get; set; }

        /// <summary>
        /// This property can be used to indicate that the current user has no privilege to perform this request.
        /// </summary>
        public bool UnAuthorizedRequest { get; set; }

        /// <summary>
        /// A special signature for AJAX responses. It's used in the client to detect if this is a response wrapped by ABP.
        /// </summary>
        public bool __abp { get; } = true;
    }

AuthenticateModel

 public class AuthenticateModel
    {
        public string UserNameOrEmailAddress { get; set; }

        public string Password { get; set; }

        public string TwoFactorVerificationCode { get; set; }

        public bool RememberClient { get; set; }

        public string TwoFactorRememberClientToken { get; set; }

        public bool? SingleSignIn { get; set; }

        public string ReturnUrl { get; set; }
    }

AuthenticateResultModel.cs

 public class AuthenticateResultModel
    {
        public string AccessToken { get; set; }

        public string EncryptedAccessToken { get; set; }

        public int ExpireInSeconds { get; set; }

        public bool ShouldResetPassword { get; set; }

        public string PasswordResetCode { get; set; }

        public long UserId { get; set; }

        public bool RequiresTwoFactorVerification { get; set; }

        public IList<string> TwoFactorAuthProviders { get; set; }

        public string TwoFactorRememberClientToken { get; set; }

        public string ReturnUrl { get; set; }
    }

Context.cs

/// <summary>
/// This class holds access token for requests
/// </summary>
public static class Context
{
    public static AjaxResponse<AuthenticateResultModel> LoginResult = null;
}

ErrorInfo

  public class ErrorInfo
    {
        /// <summary>
        /// Error code.
        /// </summary>
        public int Code { get; set; }

        /// <summary>
        /// Error message.
        /// </summary>
        public string Message { get; set; }

        /// <summary>
        /// Error details.
        /// </summary>
        public string Details { get; set; }

        /// <summary>
        /// Validation errors if exists.
        /// </summary>
        public ValidationErrorInfo[] ValidationErrors { get; set; }

        /// <summary>
        /// Creates a new instance of <see cref="ErrorInfo"/>.
        /// </summary>
        public ErrorInfo()
        {

        }

        /// <summary>
        /// Creates a new instance of <see cref="ErrorInfo"/>.
        /// </summary>
        /// <param name="message">Error message</param>
        public ErrorInfo(string message)
        {
            Message = message;
        }

        /// <summary>
        /// Creates a new instance of <see cref="ErrorInfo"/>.
        /// </summary>
        /// <param name="code">Error code</param>
        public ErrorInfo(int code)
        {
            Code = code;
        }

        /// <summary>
        /// Creates a new instance of <see cref="ErrorInfo"/>.
        /// </summary>
        /// <param name="code">Error code</param>
        /// <param name="message">Error message</param>
        public ErrorInfo(int code, string message)
            : this(message)
        {
            Code = code;
        }

        /// <summary>
        /// Creates a new instance of <see cref="ErrorInfo"/>.
        /// </summary>
        /// <param name="message">Error message</param>
        /// <param name="details">Error details</param>
        public ErrorInfo(string message, string details)
            : this(message)
        {
            Details = details;
        }

        /// <summary>
        /// Creates a new instance of <see cref="ErrorInfo"/>.
        /// </summary>
        /// <param name="code">Error code</param>
        /// <param name="message">Error message</param>
        /// <param name="details">Error details</param>
        public ErrorInfo(int code, string message, string details)
            : this(message, details)
        {
            Code = code;
        }
    }

LoginHelper.cs

  public class LoginHelper
    {
        private const string BaseUrl = "http://MyAspnetZeroApplication.com/";

        public async Task<bool> Authenticate(string username, string password)
        {
            try
            {
                var request = new RestRequest("api/TokenAuth/Authenticate", Method.POST)
                {
                    Timeout = 5000
                };

                request.AddHeader("Accept", "application/json; charset=UTF-8");
                request.AddHeader("Accept-Language", "en-US");
                request.AddHeader("Content-Type", "application/json; charset=UTF-8");
                request.AddHeader("User-Agent", "Abp.Mobile.Client");
                request.AddHeader("X-Requested-With", "XMLHttpRequest");
                request.RequestFormat = DataFormat.Json;
                request.AddBody(new AuthenticateModel
                {
                    UserNameOrEmailAddress = username,
                    Password = password
                });

                var client = new RestClient(BaseUrl);
                var response = await client.ExecuteGetTaskAsync<AjaxResponse<AuthenticateResultModel>>(request);
                if (response.StatusCode != HttpStatusCode.OK)
                {
                    return false;
                }

                Context.LoginResult = response.Data;
                return response.Data.Success && !string.IsNullOrEmpty(response.Data.Result.AccessToken);
            }
            catch (Exception ex)
            {
                //ERROR HANDLING
            }

            return false;
        }
    }

ValidationErrorInfo

 /// <summary>
    /// Used to store information about a validation error.
    /// </summary>
    public class ValidationErrorInfo
    {
        /// <summary>
        /// Validation error message.
        /// </summary>
        public string Message { get; set; }

        /// <summary>
        /// Relate invalid members (fields/properties).
        /// </summary>
        public string[] Members { get; set; }

        /// <summary>
        /// Creates a new instance of <see cref="ValidationErrorInfo"/>.
        /// </summary>
        public ValidationErrorInfo()
        {

        }

        /// <summary>
        /// Creates a new instance of <see cref="ValidationErrorInfo"/>.
        /// </summary>
        /// <param name="message">Validation error message</param>
        public ValidationErrorInfo(string message)
        {
            Message = message;
        }

        /// <summary>
        /// Creates a new instance of <see cref="ValidationErrorInfo"/>.
        /// </summary>
        /// <param name="message">Validation error message</param>
        /// <param name="members">Related invalid members</param>
        public ValidationErrorInfo(string message, string[] members)
            : this(message)
        {
            Members = members;
        }

        /// <summary>
        /// Creates a new instance of <see cref="ValidationErrorInfo"/>.
        /// </summary>
        /// <param name="message">Validation error message</param>
        /// <param name="member">Related invalid member</param>
        public ValidationErrorInfo(string message, string member)
            : this(message, new[] { member })
        {

        }
    }