Hi thanks for the comment. Indeed there was a problem with the template itself. While it did work fine on the original release of Godot 4.x, recent changes in the engine added some minor incompatibilities. These are fixed now, so just download the source code again. Thanks for pointing this out.
However keep in mind that the template expects to be installed in the root directory of your project. So if you want to put it in the subdirectory "addons", some paths in the scripts need to change as well. This isn't really complicated. Just open each file once in the editor by double clicking and you should see some kind of error regarding missing files or paths. If you don't the file should be ok as is.