It is now working. The screenshot you provided was the answer. Thanks for taking the time to answer my questions.
Just received a Dell Optiplex 3090 Ultra. I assumed I could get video over USB C cable. Apparently not true. So the problem is the Optiplex has a Display Port but the Dell monitor I purchased has an HDMI port. How do I reconcile this issue? Thank You.
Optiplex 3090 Ultra Display Problem