Unable to save iMovie file as .mov or mp4 on iPhone 16 Pro for website upload

I created a movie in iMovie from two videos. Saved to file on my iphone16pro for uploading to a website. I have done this many times on my iphone11pro. Now it won’t save as a .mov or mp4 file it saves as a movie Mobile. File??? My phone won’t let me select it for upload to site. This is an audition. I’m on a deadline. There must be a way.

[Re-Titled by Moderator]

Original Title: iMovie issue