Error PPA - FEX install ROCK4SE

Hi! I want to download FEX on my ROCK 4 SE, but the PPA does not work. See attached image. How should I solve this?

Thanks in advance!

I have tried with

sudo add-apt-repository ppa:fex-emu/fex
sudo apt update


How could I solve this?

If you had googled “rock 4 se public key not available” then the first result would have been this thread that contains the solution to fix that error -> Sudo apt update get error

export DISTRO=focal-stable
wget -O - `$DISTRO/public.key` | sudo apt-key add - 

apt update should work fine after those commands.

I have abosolutely no idea about FEX beyond that. This just gets apt update not moaning.

@mathew Yes, have written those lines earlier which solved my problem. now i am struggling with the RootFS.