Hello great people, Please can someone help me with how I can make the video display full screen on VMix and Youtube?

We currently have the SD version of VMix as a church, but whenever we connect our camera, the video does not show as full on Vmix display and YouTube without us zooming it.

It shows with black squares around it, more like video is small and inserted. However, when we zoom the X and Y from display settings, we get the output as full screen but stretching or zooming it affects the quality. Can someone please help with what we may do?

For your information, we also use a capture image from our camera to computer.

I would greatly appreciate a feedback. Thank you all.