How to mirror main display to a display with different aspect ratio

I have a presentation tomorrow and as far as I know the projectors does not match my laptop display resolution/aspect ratio. How should I configure the displays so that my main display is scaled to the projector?
I have Fedora 38, the GUI is X11-KDE plasma session.

Since you did not say what the aspect ratio is, I have to guess.
Most displays, including TVs, laptops, and desktop monitors are 16x9 ratio. The older ratio was 4x3

Any output of 1920x1080 resolution is in the 16x9 aspect. It would be strange if you have a different ratio unless you are using an ultra-wide screen. I would guess that the projector should match the aspect and resolution of your laptop

The projectors are old ones that use VGA and likely an aspect ration of 4:3

Can’t confirm without knowing the brand and model of the projector.

In my experience most projectors in the last 15 or more years will work with either aspect and variable resolution. Many monitors and projectors are still made with VGA input as one of the choices but use either 4x3 or 16x9 aspect as appropriate to the input from the screen being displayed.

Never mind I think I got paranoid over it. Everything went smoothly.