The repository 'http://ppa.launchpad.net/thomas.tsai/ubuntu-tuxboot/ubuntu focal Release' does not have a Release file. code example
Example: The repository 'http://ppa.launchpad.net/ubuntu-wine/ppa/ubuntu bionic Release' does not have a Release file.
wget -nc https://dl.winehq.org/wine-builds/Release.key
sudo apt-key add Release.key
sudo apt-add-repository https://dl.winehq.org/wine-builds/ubuntu/