How do I add a Dell monitor to my 2020 MacBook Pro?

Trying to add a Dell display to my new 2020 MacBook Pro. However, when I go to "Displays" under System Preferences, I don't find the "Arrangement" tab which is suggested for adding a display. I also tried holding down the Option button and selecting "Detect Displays," per another recommendation, but no displays were detected. I'm quite sure I have the HDMI cable correctly connected to the MacBook Pro. Any suggestions would be appreciated.