So I've been getting this error:
E: The repository 'http://ppa.launchpad.net/f-muriana/ubuntu-builder/ubuntu focal Release' does not have a Release file.
N: Updating from such a repository can't be done securely, and is therefore disabled by default.
N: See apt-secure(8) manpage for repository creation and user configuration details.
Can someone please help? Oh, I'm on ubuntu 20.04