Garmin premium hrm does not connect to Zwift

Hi, i had to buy a new arm. I chose the “premium heart rate monitor” by Garmin, as my older Polar arm do not support Ant+.

However, it does not connect with Zwift. Any ideas what I might do wrong?

By the way: I am using the Zwift App on my iMac using the Ant+ dongle of TACX.

 

Thanks in advance…

Your Garmin device doesn’t show up on the pairing screen Christian?