Xservers has a debian package repository which contain things such as builds of newer PCSX2 emulator version for debian stable. The packages are built to be used with debian stable. More packages might come in the future.
To download or update the signing key used to verify packages:
su -c "curl -4 -L -s 'https://files.xservers.dy.fi/gpg_keys/xservers.gpg' -o /usr/share/keyrings/xservers.gpg"
To add the stable repository:
su -c "echo 'deb [arch=amd64 signed-by=/usr/share/keyrings/xservers.gpg] https://deb.xservers.dy.fi/ stable main' > /etc/apt/sources.list.d/xservers.list"
Experimental repository (only use this if you really want to try packages that are experimental):
su -c "echo 'deb [arch=amd64 signed-by=/usr/share/keyrings/xservers.gpg] https://deb.xservers.dy.fi/ experimental main' > /etc/apt/sources.list.d/xservers_experimental.list"