Feature 'depth-sensing' is not permitted by permissions policy

Hello, 

i'm using a Quest Pro with WebXR, it works well, but i cannot find a way to acces depth sensing.

When intializing the context "immersive-ar" with requiredFeature "depth-sensing"

i get an error 

'XRSystem': The session request contains invalid requiredFeatures and could not be fullfilled.

Feature 'depth-sensing' is not permitted by permissions policy

According the WebXR specs https://www.w3.org/TR/webxr/#feature-descriptor

 "The depth sensing feature is subject to feature policy and requires "xr-spatial-tracking" policy to be allowed on the requesting document’s origin."

Yet, when I access the remote debugger, under "Application" tab > frames > top, I get :