Please see the Zwift forum article for instructions on connecting with ANT+.
We highly recommend using Bluetooth to connect Kinetic products with Zwift. The best option available today is using a newer Apple TV to connect wirelessly. No need for a new computer or tablet. It's a great connection and user experience with no need for additional devices or dongle extenders. See Zwift Insider story HERE.
We also have a detailed blog post on other option for pairing with Bluetooth HERE.