What iMovie version do you have?
To find out the version number of an application,
either switch to that application and go to the
Menu Bar > "Application Name" > About "Application Name" (Finder is used in below screenshot guide)
or go to the Applications folder in Finder and use the Get Info window (CMD+I).
clicking above image will get a more detailed screenshot
this screenshot uses System Preferences as example
And did you try the SHARE Menu Bar item, if it is there? There is an Export button.
You might even have luck with some of these items
To edit your thread title to a descriptive one, to get a knowledgable audience and help making the thread easier to find for people looking for the same information, just click on the
button on the bottom right of your original post and then click the
button below your message.