Changing the package name is one of the most important steps when reskinning Unity source code for Android. The package name must be unique before uploading a game to Google Play.
Where to change it
Open Player Settings in Unity, update the package identifier, review Android manifest settings, and check any SDK configuration files that use the old package name.
Before release
Build a fresh APK or AAB, test installation on a device, confirm Firebase or AdMob settings, and update store listing screenshots and app icon.
