I have an Apple Watch which I can use as a HRM in Zwift. It is wonky to connect, giving me 80-90% chance of pairing on the 1st try. Shame Apple won’t open this feature to all devices. I bought the Wahoo Tickr which Wahoo got on sale for $40. Paired easily in Zwift. It was a little janky pairing it to my Garmin 530, but got it to work. The Tickr comes with both an arm and chest strap. I use the wrist strap instead of the chest strap. Some say that it’s not as accurate as the chest strap, but how much accuracy do you really need?