Molly-UP is a branch of Molly, and this branch has been reintegrated (merged) into the main branch, so the branch is now obsolete and will not be developed further. When you want to use UP functionality in future you should install Molly or Molly-FOSS. This is what the last update of Molly-UP says in a message box when you start it these days.
Molly-UP is still in the Molly-F-Droid-repository, you can scan this QR-code using your F-Droid-client. In the same repo is the new UP-able Molly-FOSS. Uninstall Molly-UP, install Molly-FOSS, both from within your F-Droid-client.
Note: you will still need a proper QR-code for the MollySocket server for UP. This is the only method to specify the server’s address. If you don’t have any better QR-code, take this one.
You can then decide if you use your still installed ntfy or the new /e/OS distributor as I mentioned above.