In fact, it's impossible to recover files from a water-damaged MacBook Pro with a t2 chip since the SSD and the T2 chip are soldered on the motherboard. There is no way to take the SSD down separately and retrieve files stored on it. You can retrieve the files stored on it as long as you repair the MacBook Pro well and make it turn on normally.
Therefore, you should ask the local Apple stores if they can mend your Mac or if they have any way to make you out. For ways to recover data from a device with a T2 chip, read this article please: Recover data from MacBook Pro/Air 2018/2019/2020(T2 chip)
Take care~
