Android Screen sizes expanding

Hello world. I have been working on my first game for a little while, and I finished it, but only for Windows. I have been trying to convert it to an Android game, moving and everything is working as intended, but I have 1 huge problem that I can’t seem to find its solution anywhere.

I am deeply sorry for how many pictures this topic has; I couldn’t describe my problem using words.

I basically want my game NOT to adapt to screen sizes, meaning that even when the screen resolution on the android device has more width, I want it to still be in 1920x1080 / 16:9 Ratio.

In my game I have walls on the sides, when touched, these walls teleport you to the other side. I don’t want these walls to be visible, so on Windows I stuck them to the sides. I fit the yellow walls to be on the side of my main camera like this:

Here is a picture for reference: A picture of how I want my game to look on android.

And here is how it looks on some devices:

Basically, I only want the part between the yellow walls to show, without showing any part of the yellow walls. and now comes my question:
Does anybody know how to shrink the game to only show the part highlighted in blue?

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here is what happens to my main camera when the game is run on an android device btw:
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