Back to "Buster"?

Quick question:
How do I go back to "Buster" instead of "Bullseye" (i.e. Octopi 0.18.0) temporarily?

I tried the image from:
https://github.com/guysoft/OctoPi/releases/download/0.18.0/octopi-buster-armhf-lite-0.18.0.zip

But using the Raspberry Pi imager the image will not boot on my Pi4B.

The reason: I have two microSD cards, and want one for the old version, and the other for the new (keep the old version around till all the camera "bugs" are worked out of the new 1.0.0 version)

You can find all the builds here:

Thank you. I'm just a twit for not scrolling down just a bit more to see those earlier builds or looking in the wrong repository. I've been so caught up with camera issues that my brain isn't working.