Today I came across a method to install ubuntu 20.04 cli only on my xaiomi mi 8 but u may install it on any android phone
Step 1. Follow this guide carefully
It really works but I must have this link on the phone u want to install it on for it won’t work otherwise.
And towards the end there is one command in purple u must also copy and paste to run the script, before u start ubuntu 20.04 cli.
HAPPY INSTALLING !!!