Seems to be difficult. See Support for Raspberry Pi 4? and How to Get Ubuntu-MATE 18.04 up on Raspberry Pi 4 .
For RPi4 better and hassle-free way is to use Ubuntu MATE 20.04 LTS or 20.10 on it.
Seems to be difficult. See Support for Raspberry Pi 4? and How to Get Ubuntu-MATE 18.04 up on Raspberry Pi 4 .
For RPi4 better and hassle-free way is to use Ubuntu MATE 20.04 LTS or 20.10 on it.