Hi Some users try to hack our app or uses script any app type to use unlimited trick for referring
I am using user device id to track referal.
But some users uses app like island in which they do not need to root their device for changing device id. They directly uses Island app to make duplicate device in there device.
First open your app from original device
and save device full info like Device ID, imei, serial num etc in firebase or spread sheet
Then open that app by other app-cloner like island or parallel space etc
Then check what info is common/same in both devices then use that info for your project…