await update switch
{
{ Message: { } m } => HandleMessageAsync(m),
{ CallbackQuery: { } cb } => HandleCallbackQuery(cb),
_ => Task.CompletedTask
}
А внутри HandleMessage, например
switch (message)
{
case { Text: "/start" }:
...
break;
case { Text: { } t }:
...
break;
case { Contact: { } c }:
...
break;
}