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());
}