How to extract the depth map of the .heif image created with the iPhone X using imagemagick

I created an image with my own iPhone application. The image is in .heif format and contains the depth map. (I know because the Photos app recognizes it)
Now I downloaded and installed imagemagick.
and executed the following command:

magick identify -verbose orginal.HEIC

This shows me only three channels (Channel 0, Channel 1, Channel 2). I guess these are the rgb colors of the image.

How can I access the depth data of this image?