public async Task <IActionResult> OnPostAsync(int id) { try { await _externalEventManagementService.CreateNewExternalEventAsync(id, ExternalEvent.ExternalServiceName, ExternalEvent.ExternalEventId); } catch (DuplicateExternalEventException e) { ModelState.AddModelError(string.Empty, e.Message); return(await OnGetAsync(id)); } return(RedirectToPage("./Setup", new { id })); }