As you are probably aware, OctoPrint currently supports Python 2 & 3 simultaneously. Users will begin migrating to Python 3 soon and your plugin will not be installable. As of March 2021, it will switch to Python 3 only.
Please see the guide here

Having taken a look at your plugin, there is not too much Python so it should be fairly easy to sort out.
If you don't want to update it, I could PR to sort it out so Python 3 users are able to install this. Let me know what you think.