It does not appear in the Control Panel nor does it ask for permission. I was able to fix the issue by using the macOS terminal to make FFmpeg executable.

shell ~ % ls -lU /Applications/ffmpeg 
-rw-rw-r--@ 1 username staff  78461292 Aug 31  2020 /Applications/ffmpeg

shell ~ % chmod u=rwx /Applications/ffmpeg 

shell ~ % ls -lU /Applications/ffmpeg      
-rwxrw-r--@ 1 username  staff  78461292 Aug 31  2020 /Applications/ffmpeg

The Generation of Video interface is still buggy but it does now generate the video files.

@jhandgraaf said:

Hi all,
I have installed the ffmpeg on my mac but I still get the permission denied file after rendering it. I can't seem to locate in the system preferences where to authorise it? Nothing is mentioning ffmpeg?
Thanks in advance, Jerry

Did this ever get resolved?

Working on a MAC (OS 11) and when I try to save a movie. The video generation dialog builds all the frames but does not change once it shows 100%. The resulting folder shows all the png's. But the log file reads...

sh: /Applications/ffmpeg: Permission denied

If I click the "Interrupt" button it moves to next screen and when I click Save and Exit the png's disappear and just the log file is left showing the permissions error.

Also the only options for format I can choose is MPG4 or Image sequence.