Install Magisk directly to /system (Not recommended) Just flash Magisk Delta from current Magisk app
If you don’t see this, try close and open the app. In Magisk section, tap “Install” and then “Direct Install”.Install, open and then grant root acccess to Magisk Delta.Just do like when you update Magisk! Direct Install (Recommended) How to switch from current Magisk to Magisk Delta and vice versa? Magisk-files FAQ How to install Magisk Delta from start?