generally speaking, if you don't clearly indicate that "no extra ordering" is allowed in the catering group purchase package, you can ask the waiter for extra ordering if you feel hungry during the meal.

as for drinks, some restaurants may have special requirements for drinks, such as paying a certain bottle opening fee or service fee. Therefore, before you enjoy the catering service, you'd better know about the policies and charging standards of the restaurant first, so as to avoid unnecessary misunderstandings or disputes when checking out.

generally speaking, if you have any questions or needs, you'd better communicate clearly with the restaurant waiter before ordering to ensure a pleasant and smooth meal.