The file for Android 12 is a compressed Generic System Image (GSI) . It is designed for ARM64 devices that support Project Treble (specifically those with an "A/B" partition layout). Summary of Performance & Stability
Power off, then press Volume Down + Power (varies by OEM). Connect to PC. system-arm64-ab.img.xz android 12
Device support (Project Treble) - Page 3 - GSI - e/OS community system-arm64-ab
You might wonder, Why not just use the stock ROM? Here are compelling reasons: system-arm64-ab.img.xz android 12
If you want, I can: