How do you export a video as a MP4 in iMovie? I don't get that option. I'm on Big Sur with iMovie 10.3.1

I see that you can't save an edited video in Photos as a MP4. I read that you could in iMovie, but in share>file> there is no option to save it as a MP4. It saves as a .mov file.

It seems like I can convert it using QuickTime to export it as a MP4, but will there be any loss of quality?

It seems like iPhoto and iMovie should both have the option of export/save as MP4.

Well... I just found a video online where a guy says iMovie only saves video as MP4 depending on the quality; high quality is MP4 and best quality is .mov. Shouldn't that be stated somewhere?