The Milestone XProtect Mobile app must be set up before it will work with the USCSD camera system.
Open the XProtect Mobile app and tap Edit
Tap Add server
Tap OK when you encounter the prompt below
Tap Add server manually
Ensure that you enter values in each respective field as shown below, then tap Done (note that you must enter your SSO account username and password)
Tap Done once again
Tap the USCSD camera system entry you've just created for camera system access