You can install it into the ~/Library/Application Support/Glyphs 3/Scripts/site-packages.
you need to find a python 3.10, then you can run this:
/Library/Frameworks/Python.framework/Versions/3.10/bin/pip3 install --target="/Users/YOUR USER NAME/Library/Application Support/Glyphs 3/Scripts/site-packages" numpy
You need to replace “YOUR USER NAME” with the name of your user folder.