Is it useful for Meituan B&B to set an irrevocable discount?

The setting of Meituan B&B is unchangeable and useful. If Meituan B&B is a merchant version, there is no irrevocable order at present. Most of this function takes 30 minutes, or you can cancel this function for free within two hours, and it will be automatically turned on when the time comes, so you have to ask the guests to pay a certain time fee.