Root of los21/22 is very simple.
In phone just download and install last magisk.apk.
Then downloaded magisk.apk (download folder) rename to magisk.zip and copy this zip to sd card root.
Reboot phone to lineage recovery. Select install update, install from sd and select magisk.zip...wait...and reboot to lineage.
Open again installed magisk app, press install - direct install (recommended).
Done...phone is rooted 🙂