Convert an MP3 to MP4 with a black background by default

Is your feature request related to a problem? Please describe. Instagram doesn't support playing .mp3 files; the recipient can only hear a snippet of the .mp3. For example, I sent a two-minute .mp3, and the recipient could only listen to the first 30 seconds; otherwise, they had to use the "audio transcript" feature.

My solution was to convert the .mp3 to .mp4. However, when I right-clicked and used File Converter, I couldn’t convert the .mp3 to .mp4. So I used Premiere Pro instead.

Describe the solution you'd like Is it possible to add an MP4 conversion option where, by default, the "video frame" would be a black background? This would simply make the conversion process faster and run locally.