Water damage repari

If you’re in the U.S., expect to pay a minimum of $329 plus tax, assuming Apple chooses to even consider a water damaged iPhone for repair.

iPhone Repair - Official Apple Support

Water and other liquid damage to iPhone or iPod isn't covered by warranty - Apple Support

Apple doesn’t repair water damaged devices. They will offer an out of warranty replacement of the entire device. In the USA that out of warranty exchange fee for an iPhone 6s Plus is $329.