I do not have the option in my Garmin connect app to link to Vitality. I only have strava, myfitnesspal and Microsoft office. ive got the vitality UK app installed on my phone. I can't see anywhere in the app or on the website to link the two.
This is quite normal, the Vitality app does not show in Connect. You need to go in to Vitality App and Rewards. You should see if the Garmin device is linked or not. If the latter, you can connect it from there.
This was resolved by going to the Vitality website, then Partners and Rewards section and selecting "Link Device" then choosing Garmin. Strangely, Garmin aren't an available option to select if you are using the app.