Install GAPPS with ROOT

• Download right Android and ARM64 from [here]https://wiki.lineageos.org/gapps/=
• With the magiskgapps.com convert to Magisk module
• Download and push outputted file to tablet

adb push MagiskGAppsMaker.zip /storage/emulated/0/Download 

• Open Magisk app and go to Modules section
• Click Install from storage button
• Choose pushed file and install it, then reboot
• done!

Fix audio via jack with ROOT

• Enter android console

adb shell

• Enable audio

su
setprop persist.sys.overlay.devinputjack true

Fix audio via jack without ROOT

• Go to the Treble settings
• And enable Use alternative audio jack detection
• Reboot