Not sure if klipper works without a pi. Installation is the same for pro version. Actually only difference is that you enter a license code to activate extra features, but does not change login problem or anything else.
Yes just follow klipper installation instructions. Image also has python and can be installed just as described. Just replace what is described for octoprint with same action in repetier and select klipper as firmware in server.
Comments
https://www.repetier-server.com/knowledgebase/password-forgotten/
on how to reset all users so you have no password required again.
Installation is the same for pro version. Actually only difference is that you enter a license code to activate extra features, but does not change login problem or anything else.
https://www.repetier-server.com/knowledgebase/connection-problems-with-printer/