Restrict user to upload only flac and aac file

I am trying to configure Nextcloud server to only support Flac and AAC file. I tried file access control and it works for all format except Flac and AAC.

Can you guys please help me with the same?

Please always describe/ show, what you already tried and what didn’t work.

So could you please show your current rule sets, especially the one for flac and aac, please?