How to make a live texture of what a camera sees?

Hello, I’ve recently been wanting to create Non-Euclidean geometry and I wanted to see if I could do a faster way of making a live texture. I want the texture to be like what a certain camera in the workspace sees, like Render Textures in Unity. I really just don’t know how to do this without using the video editor and holdout textures in a tutorial I saw (stitching different videos together)

Here’s an image of what I am trying to do (an example)