When you turn off "enable debug" you need release key (in the text that follows called release.keystore).
In console (I tried it on LInux, but I thing it also should work on Windows) you can use this command:
keytool -genkey -v -keystore release.keystore -alias yourKeyAlias -keyalg RSA -keysize 2048 -validity 10000
Replace "yourKeyAlias" with alias of your choice. It will ask you several questions (name, organization, country, etc.), which I think you do not need to fill and a password.
After that the "release.keystore" should be created. Then in Godot android export in paragraph called "keystore" in Release set path to release.keystore, in Release user fill "yourKeyAlias", in Release password fill your password.
Then, when exporting, turn off the enable debug.