public async Task <IActionResult> AddNewInvitation(InvitationVM invitationVM, int groupId) { if (ModelState.IsValid) { string result = await invitationRepository.AddNewInvitation(invitationVM, groupId); if (result == "Sukces") { return(RedirectToAction(nameof(AddNewInvitation), new { isSuccess = true, groupId = groupId })); } else { ModelState.AddModelError("", result); } } return(View()); }