LoginAction.cs

[HttpPost]
[AllowAnonymous]
[ValidateAntiForgeryToken]
public async Task Login(UserCredentials userCredentials,
	string returnUrl = null)
{
    ViewBag.returnUrl = returnUrl;
    var returnTo = "/Account/Login";

    // Replace this with your custom authentication logic
    if (userCredentials.Username == "user1" &&
        userCredentials.Password == "pass1")
    {
        var userInfo = new UserInfo
        {
            FirstName = "UserFName",
            LastName = "UserLName"
        };

        var accessTokenResult =
                  tokenGenerator.GenerateAccessTokenWithClaimsPrincipal(
                    userCredentials.Username,
                    AddMyClaims(userInfo));

        await HttpContext.SignInAsync(accessTokenResult.ClaimsPrincipal,
            accessTokenResult.AuthProperties);

        returnTo = returnUrl;
    }

    return RedirectToLocal(returnTo);
}