Need URL to pull Snapshot from Camera behind NVR

[WA3PNT]

I have a need to "pull" a Snapshot from a Camera that is connected to the NVR POE ports.
The NVR IP is 192.168.0.101, Port 8888
The Cameras are various 10.1.1.X addresses.

I need to do this from a program that is running on the 192.168.0.1 LAN, and do not want to have to enter the USER and PASSWORD manually. It should be included in the URL.

I have googled and searched, and found some URLs that "almost" work, but require the entry of the User and Password before displaying the Snapshot.

Here are a few URLs that I've tried:

http://192.168.0.101:8888/onvifsnap...inpas=gbs99039903snapshot?channel=3&subtype=0

(requires the entry of the User and Password)

http://192.168.0.101:8888/loginuse=...subtype=0?username=admin&password=gbs99039903

(requires sign in to the site[NVR])

http://192.168.0.101:554/admin:gbs99039903/cam/realmonitor?channel=3&subtype=0

Message says this Page is not working)

Any help appreciated.

RodeoGeorge