FPS games in vertical are a little weird to do. you have to pack a lot of information in a strange way
if you use premiere, you can follow the workflow i use when i work for clients
example from client i worked for:
https://i.imgur.com/Rx8scSn.png
if you don't have a facecam you can replace that dead area with whatever you want or even make it the killfeed instead
the way i accomplish this in premiere is by just creating 4 layers in a group of all the same footage, cropping each piece of footage how i want it.
layer 1: gaussian blurred footage stretched to fit the frame as background
layer 2: gameplay footage shrunk and centered to give most of central view
layer 3: facecam
layer 4: killfeed between gameplay + facecam
if you want this project file to use as an example let me know
video in motion: https://www.youtube.com/shorts/FtEzSu6YKyM
edit apologies my brain mentally blocked out the word vegas but the workflow should be similar at least if you know how to do that on your own lol