Today I wanted to make a “vertical” render to the Key-visual project, but in the Blender by default camera has a fixed “horizontal” resolution 1920x1080px.
To change resolution, you need to select the camera (object), then go to the Output properties in the right sidebar (3rd button from the top) and in the Format section you can change X-Y values. I used 1500x2250px for my Key-visual project for the game.