Graphics Card Twin Monitor Total Control?

I have recently purchased an MSI NVIDIA GEFORCE GTX 1660 Super, VENTUS XS OC EDITION, graphics card. It seems to be working well.

It is the case that the card has one HDMI port at the back, and that my (MSI) motherboard has one HDMI port at the back of it. I am running two monitors at the same time.

-Is it the case that the NVIDIA graphics card has assumed total control of both monitors? The graphics card itself only has one HDMI slot, not two of them. If the NVIDIA graphics card has not assumed total control of both monitors, is there a setting that I can alter to make that happen? And if so, could someone issue a reply to my question here talking me through/showing me how to alter the appropriate setting so that I don’t have onboard motherboard graphics controlling my twin (2) screens, but that the NVIDIA card does so, despite that one screen remains plugged into the motherboard HDMI port?