Well, i didn't have any less-than-3MB mp3 videos, and my copy of VLC will only convert other formats to audio MP3.
(it's happy to make mp4 videos)
That said, here is the result of creating a short audio mp3 file ... the audio of a howler monkey we found in Costa Rica:
View attachment HowlerAudio.mp3 (1.6 MB, 1:44 run time)
So, at least for audio, i seem to be able to upload to the forum
(Windows 10 laptop, Google Chrome browser, the free VLC media converter creating the file... but as audio)
added: when i clicked on that, it didn't *play* it, it merely caused by browser to download it.
--dick
p.s. you could always zip the file as an alternative upload format. StuffIt can do that.