I damaged my Galaxy a71 a few days ago. Remove the sim card tray and allow to dry for 48 hours (or more) under a fan, or preferably with silica gel packets. Make sure the phone is completely dry, and there is no fog in any of the cameras, after this you can attempt to reboot the phone, it may need to be plugged in for it to power on. This worked for me, however i am allowing the phone to dry under a fan for even longer after the ultrawide, and macro camera did not work, and the volume up button was malfunctioning. Personally i allowed it to dry for around 4 days before i attempted to power the phone back on.