ubuntu/linux mint PPA does not work

[ROSt52]

LM 20 Cinnamon.

I wanted to use the command:

sudo add-apt-repository ppa:freefilesync/ffs


to get the PPA installation. However, I get the error message

This PPA does not support focal

Source of the command: http://ubuntuhandbook.org/index.php/2013/12/install-freefilesync-6-ppa-ubuntu-1310/

Helping comment is appreciated!