It seems that the Filament Manager plugin no longer works with newer Octoprint installs.
I found this out the hard way when the PC I was running Octoprint on died and I needed to rebuild it.
After restoring from an Octoprint backup everything worked except Filament Manager. Looking at the devs github I doubt there's much hope of it being fixed.
So the question is there another way to get the same functionality as the filament manager plugin? It was nice being able to keep track of my inventory.
Typically in this case the best thing to do is look at forks that people have fixed things that may be broken. For example, the link below from my fork was working in my windows install the last time I tested it with python 3.10. Copy paste the URL below in Plugin Manager > Get More > ...from URL and click install and see if it will install for you then.
https://github.com/jneilliii/OctoPrint-FilamentManager/archive/refs/heads/fix-python-10-compat.zip
You might also want to check out Spool Manager. I think it was adopted, and the maintainer was going to start porting some of the features from Filament Manager over to it.
I just came back to report that I found Spool Manager and Spoolman as options after I posted yesterday. I decided on Spoolman along with it's octoprint plug-in
After configuring it seems that it will do the job.
It's a bit more complicated to use than Filament Manager but not too bad once you figure out the workflow. And you don't need to go into the Octoprint UI to manage filaments as it's a standalone app.
Thanks for the suggestions tho.