How much does it cost to repair the front camera from water damage on a 2021 iPad Pro?

You can use this website to check the estimated cost depending if you have AppleCare+ iPad Service & Repair - Apple Support

Most Apple Store locations do NOT do actual repairs of an iPad.

Most Apple Store locations ONLY do in/out-of-warranty device replacement.

If you purchased paid, extended AppleCare+ for your expensive iPad Pro, a replacement iPad Pro will cost you a small $49 U.S.D. device replacement fee.

If NO paid, extended AppleCare+ on this expensive iPad Pro, device replacement will be an expensive and costly 60% of the original OEM Apple purchase price of that iPad Pro.