Hi, when dealing with new stuff like this I tend to take a scattergun approach, so maybe one of the following steps was what did the trick for me, so as best I can recall this is what I did:
1. Download and install Python 3.7.9 on Windows 11, probably choosing the default options, including the one to set the PATH variable
2. Download the github contents into a folder, F:\Software\Python in my case
3. Amended server.py with the IP address of my WiiM Mini
4. As I recall, I did pip installs for each import line in that script e.g. pip install upnpclient, pip install xmltodict etc - I think some may already have been included in the core Python system anyway, but I still ran thru each. I may have run a pip update first too i.e. pip install --upgrade pip
5. Followed the instructions for the chrome extension at
http://mytypings.com/converting-website-to-a-google-chrome-extension/
6. Set up a small batch file wiim.bat in that same folder to run up the server with the lines
CD f:\Software\Python
.\server.py
exit /b
7. When I fire up my PC, I run that batch file then click on the extension in Chrome, and all's well...
If I remember any other steps I took, I'll come back and update this