This offer cannot be revoked.

The withdrawal of an offer must arrive before or at the same time as the offer, but the revocation of an offer reaches the offeree before the offeree sends a notice of acceptance, so it is no longer a withdrawal of the offer.

Article 19: An offer shall not be revoked under any of the following circumstances:

(1) The offeror has determined the commitment period or expressly stated in other forms that the offer is irrevocable;

(2) The offeree has reason to believe that the offer is irrevocable and has made preparations for the performance of the contract.

I hope you are satisfied