Sorry, but it is true. Support was withdrawn by Zwift a while back. Some people do still have it working, but you won’t get any help from Zwift themselves on it until they bring back Apple Watch as a supported device.
Zwift announced that support was coming this winter, (23/24) though it hasn’t appeared yet and yesterday’s layoffs will undoubtedly shake up schedules.
If you’re interested in a workaround while you wait for a fix, try using the Heartcast or Echo app with your watch. I tested Heartcast recently and it worked.