public async Task <IActionResult> OnGetLinkLoginCallbackAsync() { var user = await _userManager.GetUserAsync(User); if (user == null) { return(NotFound($"Unable to load user with ID 'user.Id'.")); } var info = await _signInManager.GetExternalLoginInfoAsync(user.Id.ToString()); if (info == null) { throw new InvalidOperationException($"Unexpected error occurred loading external login info for user with ID '{user.Id}'."); } var result = await _userManager.AddLoginAsync(user, info); if (!result.Succeeded) { StatusMessage = "The external login was not added. External logins can only be associated with one account."; return(RedirectToPage()); } await _userManager.RefreshExternalLoginFeatures(user); // Clear the existing external cookie to ensure a clean login process await HttpContext.SignOutAsync(IdentityConstants.ExternalScheme); StatusMessage = "The external login was added."; return(RedirectToPage()); }