iphone won't turn on, not registered to icloud account, activation lock is on and I want to turn it off

My daughter dropped her iphone in the toilet. We cannot get it to turn on, but I would like to trade it in for damage credit. However, the activation lock is on. When we log in to her iCloud account and her Apple ID account, the phone does not show up anywhere. Find My iPhone doesn't work because it won't turn on. How do I get the activation lock off so I can get rid of this device?