Please note that the app in the App Store is not a Universal App. Only the version from the developer website is M1 optimized.
Click on Displays icon in the upper-right corner of your screen and choose your monitor resolution among all supported resolutions. Displays is listing even resolutions hidden by macOS.
Displays supports all active monitors attached to your Mac, including AirPlay monitor. With one click, you can enable or disable mirroring mode.
To easily identify a resolution, you can set a custom label instead of resolution width/height and you may choose or not to group Retina resolutions, and even hide too-small resolutions.