XRFrame.getDepthInformation()

getDepthInformation(view)

// Make sure  to request a session with depth-sensing enabled
const session = navigator.xr.requestSession("immersive-ar", {
  requiredFeatures: ["depth-sensing"],
  depthSensing: {
    usagePreference: ["cpu-optimized", "gpu-optimized"],
    formatPreference: ["luminance-alpha", "float32"]
  }
});

// ...

// Obtain depth information in an active and animated frame
function rafCallback(time, frame) {
  session.requestAnimationFrame(rafCallback);
  const pose = frame.getViewerPose(referenceSpace);
  if (pose) {
    for (const view of pose.views) {
      const depthInformation = frame.getDepthInformation(view);
      if (depthInformation) {
        // Do something with the depth information
        renderDepth(depthInformation);
      }
    }
  }
}