What I had to do was add the Ubuntu 18.04 repo to my Ubuntu 20.04 computer
this helped me: https://askubuntu.com/questions/1252490/how-to-add-18-04-repo-to-20-04
after that update and it will be install-able now.
@calbzam I think you guys should just do a snap it would easily solve this issue ...
Will Linux get continued support?