My son is in Macao right now he was given to stay until 28 of September, can he asked an extension to stay if he will have a return to PRC

Then after that he will travel to Malaysia with a return ticket to Macao. There in Kuala Lumpur he will stay for one month and he will come back to Macao. Does the Macao immigration give him a free visa again? I need an answer to this question.