No. Your Xs Max is water resistant, NOT waterproof. At no time has Apple EVER suggested any iPhone is waterproof and specifically, Apple's warranty says water damage is NOT covered under warranty. There is a big difference between water resistant and waterproof. The rating you're referring to is under lab controlled situations. Dropping your phone, especially dropping it into water is not a lab controlled situation.
You will have to pay Apple to either fix the phone if they can, but they usually will not attempt to fix a water damaged phone. Instead, Apple will offer you an Out of Warranty replacement at about 60% of the cost of the phone when it was new.