How do I know if OMGF (Pro) is working?
Using F12, you can open up the developer tools of your browser. Then head over to the Network tab and reload the page (CMD + R on MacOS or CTRL + R on Windows/Linux.)
You'll see the "waterfall" of requests populating. In that waterfall you shouldn't see any requests to fonts.googleapis.com or fonts.gstatic.com. If you do, please send me a message, so I can have a look. If you're not an OMGF Pro user, please include the site's URL.