LinuxCNC 2.8 Buster on VM

Hi,
my machine is still using 2.8 with buster.

Now i wanted to setup a virtual machine to test some changes at home which i want to make. But if i run sudo apt update it shows me that linuxcnc.org/dists/stable/InRelease ist not available. In my sources list i use linuxcnc.org dist: buster 2.8-rtpreempt base 
i guess there is something like a archive adress but i don't find it in the documentation.. 

Also i would like to install the older probe basic version which i use on my machine. I dont want to change to 2.9 as there are too much changes and i don't even know if its running on my machine which uses quite old hardware.. But the documentation only shows the dist for the latest version with python3.11.. 

br
 

Any progress on this?
You can always use a USB to boot LinuxCNC from it and use it even to control the machine, without installing anything.
Will not work for Probe Basic as that needs to be installed, though.