Translations:Amlogic TV boxes/49/en
From Manjaro
Next, install and run Magisk under Android. When installing Magisk, choose Recovery mode then select the Select and Patch a File method. You will then be asked to locate the backup of the boot partition we created with TWRP so navigate to SD card/TWRP/BACKUPS/1234567890/SOMEDATE/boot.emmc.win and double-click the boot partition image file then choose Let's go. Magisk will then patch the ramdisk within the boot image and create a new recovery image called magisk_patched-something.img that gets saved to your Android Downloads directory. Copy this new image file from Downloads onto a micro SD card and rename it recovery.img so that you can multiboot from it, rooted.