public async Task AddClient()
{
ClientModel client = new ClientModel
{
FirstName = FirstName,
LastName = LastName,
Email = Email,
Phone = Phone,
Address = Address
};
await _clientEndpoint.PostClient(client);
client.Id = await _clientEndpoint.GetClientID(client);
Clients.Add(client);
NotifyOfPropertyChange(() => Clients);
ResetClientModel();
}