One of my Flatpak application stopped working properly, probably after a silent upgrade. I found a fix online that tells me to add a parameter. That fix works. Nonetheless, I like running that app from the GUI as it's much less time consuming than typing its full name in the console.
For a concrete example, my program is VSCodium, installed with Flatpak. The fix is to run it with GPU disabled.
Currently, the GUI runs the command flatpak run com.vscodium.codium with probably a few more parameters, I would like it to run flatpak run com.vscodium.codium --disable-gpu, keeping those extra parameters.
If it were an app installed through the native package manager, I'd modify the .desktop shortcut, but I can't find the ones created by flatpak, if any.
How do I achieve that? (Where are the .desktop files or is there a better way?)