Garmin watches are partially supported by Gadgetbridge [1]. I have not used it, but it seems to at least support basic data for many Garmin watches. [1] https:

Garmin watches are partially supported by Gadgetbridge [1]. I have not used it, but it seems to at least support basic data for many Garmin watches. [1] https://gadgetbridge.org/gadgets/wearables/garmin/ https://gadgetbridge.org/gadgets/wearables/garmin/