Upgrading from Android 7 to 8 manually is risky. Do not proceed without checking these boxes.

Go to Settings > About Phone > Build Number (tap 7 times). Then go to Developer Options and enable:

– If your device supports Project Treble (unlikely for most Android 7 phones).

There are two distinct ways "Upgrade Android 7 to 8" is usually meant. Please clarify which you are looking for:

Android OS updates require changes to the system partition, kernel, drivers, and framework – things an APK (which runs in user space) can never touch. At best, fake “upgrade APKs” are: