Replace Garmin username/password by OAuth flow and tokens

[stv0g]

Do we really need to provide the username and password?

I guess having a similar authentication flow as for the Withings API should be possible

[jgrecu]

I guess it would be possible: https://developer.garmin.com/gc-developer-program/health-api/ but getting into the Garmin developer program is not as easy as with Withings. and documentation is well hidden. (https://connect.garmin.com/proxy/oauth-service-1.0/)

[matin]

Garth migration solved this