- Download the Magisk manager application from Magisk
- Get the boot.img file from your rom folder.
- In case of a payload.bin package use payload-dumper-go to unpack all the images and get the boot.img
- Patch it with magisk.
- Copy the magisk patched boot image to your pc.
- Reboot to fastboot
> fastboot flash boot <magisk_patched_boot_img>
> fastboot reboot