I thought I had everything all set up, but when I logged in to Garmin Connect, I didn't see any data from My Fitness Pal. When I tried going through the app on my iphone, I could just see a dark blue screen on the Garmin side.
So I went through the websites, and after a few disconnects and reconnects, I am seeing the data sync.
I used my computer because the Garmin Connect App wasn't showing the a way to connect.
On the My Fitness Pal Side:
Go to Apps
Choose Garmin Connect - Get (which brings you to Garmin and you have to login)
On the Garmin Connect Side:
Go to Calories In/Out and choose Connect on the lower left of the screen. I already connected mine before I did a screenshot and I am not going to risk unconnecting it now that it is working.
I had to do this a few times, and then suddenly it started syncing. Garmin wouldn't finish syncing, so again I disconnected and reconnected.
Perseverance pays. It works.