public async Task <IActionResult> OnGetAsync(string returnUrl = null)
{
returnUrl ??= Url.Content("~/");
await HttpContext.SignOutAsync(IdentityConstants.ExternalScheme);
PageTitle = await TranslationsService.TranslateAsync("inloggen");
TxtUserName = await TranslationsService.TranslateAsync("username");
TxtPassword = await TranslationsService.TranslateAsync("password");
TxtRememberMe = await TranslationsService.TranslateAsync("Remember me");
TxtRequiredPassword = TranslationsService.TranslateRequiredError(TxtPassword);
TxtRequiredUserName = TranslationsService.TranslateRequiredError(TxtUserName);
ReturnUrl = returnUrl;
return(Page());
}