Zwift compatible treadmill - what does that really mean?

I am wanting to buy my wife a Zwift compatible treadmill. I looked at the compatability page* and its not really very helpful, just listing some manufacturers.

So I went to some manufacturer web sites eg <lifespan Apex Smart 2 Treadmill> (in my budget and it needs to fold) and it says Zwift compatability, but the manual doesn’t mention Zwift. The specs do say bluetooth under the smart display section. So is that how the Zwift app on your phone / ipad etc actually get a speed signal?

*sorry no links allowed

The treadmill emits speed and sometimes cadence to Zwift via Bluetooth.

If the advert/ manufacturers page says Zwift compatible then it should be the case. Most treadmill manuals aren’t that comprehensive and tend to avoid mentioning specific apps other than their own software if they have it.

The list of Zwift compatible treadmills is useful and does list specific models but its very often not up to date.

The model you’ve targeted i cannot find anything that says it’s Zwift compatible. It has Bluetooth and links to it’s own app. This does not mean it’s Zwift compatible.
And the reviews are quite poor on general for it.