The save file is located on windows by default at: windows ~ C:\Users\USER\AppData\Local\NovaDrift\ (may have to show hidden folders to see) on windows (other platforms do not have a singular save location and must be checked depending on the default save location for macOS and linux - the latter depends on whether Proton or WINE is being used). Save file is called save.ini

Open the save file with a relevant program (e.g. notepad) and type ctrl + f (or whatever relevant search function that program uses) and search for "windowedHeightAspect=" (without the ") and manually set the number to the desired value (no less than 720). In the row below that, manually set the number to the desired value (no less than 1280) while maintaining an aspect ratio between 16:12 and 16:9.