This shows geolocated information of some of the Apple iCloud Private Relay egress points. It's a little over half of them, those I could geolocate with the information I had to hand, but it gives an idea of the coverage.

When someone connects to your webserver via iCloud Private Relay or loads an image from an email using Apple Mail Privacy Protection the load will come from one of Apple's egress IPs, and that IP will geolocate (using standard commercial geoIP databases) to one of these locations. For MPP or Private Relay in it's default "Maintain General Location" mode it will be from one relatively near where Apple believes the user is.

Click to zoom, drag to scroll. It's dragging 100k+ locations around so it'll be slow.