public async Task <IActionResult> OnPost() { if (ModelState.IsValid) { var user = await _userManager.FindByNameAsync(LoginModel.Username); if (user != null && await _userManager.CheckPasswordAsync(user, LoginModel.Password)) { return(await HandleMerge(user, Url.Page("MergeConfirmation"))); } ModelState.AddModelError(string.Empty, "Invalid credentials"); } await GetMergeLoginViewModel(); return(Page()); }