Ларавел Прикрепитель
//id for single
$user->reasons->attach($reasonId);
//array for multiple
$user->reasons->attach($reasonIds);
$user->save();
Freeburn
//id for single
$user->reasons->attach($reasonId);
//array for multiple
$user->reasons->attach($reasonIds);
$user->save();$book = App\Book::find(2);
$book->authors()->attach($authorId);