Refit + Prism Forms + Fusillade + ModernHttpClient (LoginPageViewModel)

LoginPageViewModel.cs

//Constructer Creation
public partial class LoginPageViewModel
{
    public LoginPageViewModel(INavigationService navigationService, 
                              IApiService<IAuthenticationService> authenticationService)
    {
        NavigationService = authenticationService;
        AuthenticationService = authenticationService;//Here you will get AuthenticationService object injected
    }
}

//Variables Declaration
public partial class LoginPageViewModel
{
    IApiService<IAuthenticationService> AuthenticationService { get; set; }
    INavigationService NavigationService { get; set; }
}

//Bindable Properties
public partial class LoginPageViewModel
{
    private string userName;
    public string UserName
    {
        get { return userName; }
        set { SetProperty(ref userName, value); }
    }

    private string password;
    public string Password
    {
        get { return password; }
        set { SetProperty(ref password, value); }
    }
}

//Commands Creations
public partial class LoginPageViewModel
{
    public DelegateCommand LoginCommand => new DelegateCommand(OnLoginCommandExecuted);
}

//Private Methods
public partial class LoginPageViewModel
{
    async void OnLoginCommandExecuted()
    {
        try
        {
            IsLoading = IsBusy = true;
            //Calling IAuth Service, AuthenticateUser method to check user credentials are valid/not.
            string userCredential = "Basic " + Convert.ToBase64String(System.Text.Encoding.ASCII.GetBytes($"{UserName}:{Password}"));

            var response = await AuthenticationService?
                                .UserInitiated?
                                .AuthenticateUserAsync<AuthenticationModel>(userCredential);

            if (response?.Status == System.Net.HttpStatusCode.OK)
            {
                await NavigationService.NavigateAsync("../" + nameof(DashboardPage));
            }
            else
            {
                throw new UnauthorizedAccessException();
            }
        }
        finally
        {
            IsLoading = IsBusy = false;
        }
    }
}

Step 1 : - https://gist.github.com/hamid-shaikh/24d93419f9b5313685c4dfc40f4b59dc
Step 2 : - https://gist.github.com/hamid-shaikh/7a766529e79cea8e108d53c657ca1594
Step 3 : - https://gist.github.com/hamid-shaikh/803e88151281e24bc07fba2a4903cc49
Step 4 : - https://gist.github.com/hamid-shaikh/082fea0c0bb3accc7c1db180d81a9884
Step 5 : - https://gist.github.com/hamid-shaikh/0774fe04cf7121c0d596925c93fc1809