In RKDevTool , go to the "Upgrade Firmware" tab. Click the "Firmware" button to browse and select your downloaded .img file.
“RK322Xbox” was the key. A custom ROM, stripped of Google’s claws, optimized for Rockchip’s RK3228 and RK3229 chipsets. The “712” meant Android 7.1.2 — Nougat, old but gold. And “NHG47K” was the build fingerprint, spoofing a Nexus device so Netflix and YouTube wouldn’t complain. android rk322xbox rk322xbox 712 nhg47k install
After a fresh install, the first boot can take 5 to 10 minutes . Be patient! In RKDevTool , go to the "Upgrade Firmware" tab