On some videos, I get the error message Output format mp4 is not available. Downgrading to ffmpeg 6.1.1 fixed this error so it looks like the app needs an update to be compatible with the latest major version of ffmpeg. In the meantime, your users can use 6.1.1 as a workaround. The easiest way to do this is probably to use a package manager. I'm on Windows atm so for me it's:

scoop install [email protected]

Then they can configure the ffmpeg path in their config.

path.to.ffmpeg = ~\scoop\apps\ffmpeg\6.1.1\bin\ffmpeg.exe

If the ~ doesn't work, replace it with the user's home dir, e.g. C:\users\USER.