Game Save Permission required


By default, if I use the GameSave process in Shipping Android (google play) game, the file is not stored at all. So the user progession is not available.
I read that I can check a box for ‘ExternalFiles’ but the data is rested at each install (as per comment);

What permission should I set in ProjectSettings to get the grants to write this file ?
Do I need to change anything else out of getting the permission?