In-Game Camera Screen

Hello! I am making this topic regarding a specific issue: I am trying to have a screen in my game show a stage through a camera. I have tried using Viewport Frame, however to no avail. I might not be setting it up right, or something. However, I have given it my all and decided to come here in the end.

Here is the main stage;


As you can see, I am trying to have the big screen on the top show the main stage where the camera is on the bottom. Would anyone happen to have any ideas?

I have tried the following post as well;

Any help is appreciated, thank you!

try this:

its a viewport frame handler and you can see on this post in that topic is what you may need