Wahoo ANT+ dongle won't pair with Zwift

Wahoo ANT+ dongle won’t pair with Zwift
Purchased brand-new Wahoo ANT+ stick & ext. cord from REI yesterday, plugged it in according to Zwift’s YouTube video. But stick does not seat all the way inside the end of the cable (with other end inserted in USB port on MacBook Pro–running High Sierra). Should I use more force when connecting the ANT+ stick to the cable? Meanwhile, I’ve tried plugging it into the trainer’s USB port but was not able to pair with Zwift.

The ANT+ dongle goes into the computer’s USB port, either directly or at the end of a USB extension cable. It enables the computer to communicate over ANT+ radio signals with the ANT+ radio in smart trainers.

At first, the ANT+ stick would not seat into the end of the cable properly, so instead of trying to force it I assumed it was supposed to plug into either the computer or the bike’s onboard monitor. After another try, the stick attached to the cable completely. I’ll attach the cable (with ANT+ stick connected) to the computer. Thx again.