Passing parameter to a Screen

[samyuhaifeng]

I want to pass a parameter to PostEditScreen.php, such as category id to ProductEditScreen, how should I do it? I try to add
'myid' by Route::screen('post/{post?}/{myid?}', PostEditScreen::class)->name('platform.post.edit');
but when I want to create a new post, it is always editing the same one, what should I do in createOrUpdate function? or in query function? thanks a lots!