How do I reverse a video on iMovie app on my iPhone 15 Pro Max without the reverse button?

The “reverse” button is missing from my iMovie app (v3.0.5, just reinstalled from App Store 6/3/25) on iPhone pro max 15/ios 18.5. Prior help says it should be on the speed menu, but isn’t anywhere. How can one get it (back) or time-reverse a video on iPhone without a 3rd party app or web?

[Re-Titled by Moderator]

Original Title: reverse function missing on iPhone iMovie