Root with Magisk

Click Install under the Magisk submenu on the right.
Will need an airmouse or USB PC mouse.

Choose 'Select and Patch a File'

Now browse to the boot.img and select it.
Now click 'Let's Go'

A patched boot.img will be generated in the Internal_Storage_Downloads folder.

Go to About

Click 7 times on 'Build'

A new 'Developer Options' menu will appear.

Go to 'Select Image to flash'
' image.jpg

Select the patched boot.img in the Downloads folder
Try to remove any USB storages so that unnessasary images from them don't appear in this menu.

Select the 'boot' partition

Now reboot and your device will be rooted.

Link to boot image that can be copied to device and patched with Magisk

Magisk app can be downloaded from Unlinked App Store in AndroidTV firmware v1.4 - Code StationPC
or here

Inside Magisk Settings you can enable
Zygisk and DenyList to add apps to block root from eg. streaming apps while other apps can still use root correctly.

To pass Safetynet, you can use Universal Safetynet Fix and install it as a module.
More info here