Can Keynote export a recorded presentation to mp4?

I need to record a slide show with my narration (built-in microphone) to submit to a conference, and the recorded file must be in mp4 format. My presentation is a Keynote (.key) file.

The easiest way for me to record while seeing my notes is to use the Record function in Keynote. But as far as I can tell, Keynote produces only m4v format recordings, which are not acceptable.

Is there a way to get Keynote to record a presentation in mp4 format? Alternatively, is there a safe way to convert an m4v recording to mp4?

I'm on a MacBook Pro (Retina, mid-2015) running MacOS 10.15.7 (not converting to Big Sur until certain bugs get resolved, certainly not before my presentation is due).

I'm using Keynote version 10.3.9 (7029.9.8)