I was going to add the ability to embed Garmin Connect activities just like Strava activities and segments, but it turns out they put up a $5000 paywall
in front of their API back in Feb 2014
What a dumb move by a company that is clearly out of touch with reality - interconnection is not a feature, it's a requirement. The "modern" Connect UI is so far behind the competition, without 3rd party developers, it will just continue to slide into irrelevance. The only thing I use it for is auto-sync to Strava.
So, no Garmin activity embedding on Staminist any time soon, sorry.