Can not use AREarthManager.CheckVpsAvailability()

In Geospatial API documentation, says

Check VPS availability in your app The Geospatial API can be used in any place where the device is able to determine its location. If your AR experience hinges on VPS coverage, you can use AREarthManager.CheckVpsAvailability() to obtain a VpsAvailabilityPromise, an asynchr开发者_如何学编程onous task that checks the VPS availability at a given horizontal position. Once you have the VpsAvailabilityPromise, you can obtain its result by polling.

But I can't use it. It doesn't exist. I know that this is static func...

I need to check if VPS is enabled or not. I just wonder why the function described in the official documentation doesn't exist.