Sorry for the necro reply, but this is the same question I have. I did find a tool set on GitHub - https://github.com/leonboe1/GoogleFindMyTools - which is used for creating 'custom' advertising keys (for developing trackers) and requesting the current location (Lat/Long) of a registered tracker on your Google account and when.
So I would run python main.py, it would return a list of my registered trackers. I would enter the numeric value of the tracker I want information for, then it would do a number of tracking-related requests, including requesting and decrypting the latest tracking data (location and last located date/time).
What I'm not sure of, however, is how to turn those results in my CLI into something that can be transmitted to HomeAssistant, as well as creating 'devices' for the tracked devices and entities/sensors for the curr location, last date/time, etc.
I use trackers for my typical important items but also my cats. Having that information displayed on a map, and better yet automatically notify me for out-of-range would be fantastic.