This is 100% unofficial. Phone makers don't want you to install third party roms (they cease having any control, won't receive analytics, can't push ads etc). Why should they help you out? They'll do the bare minimum (or less) that is required for you, the owner, to be able to use third party roms.
emli42
joined 1 year ago
Put simply, you don't. If your phone is supported and the documentation is there, the installation is a breeze.
I'm not here to defend them, but many consumables can be bought from third parties. There's even an upcoming Revo nozzle adapter.
Not sure if a Chinese app will offer more privacy.