add a song to imovie

If you are referring to "protected" songs, those would be songs with DRM (Digital Rights Management) protection. They cannot be used in iMovie. All Apple Music songs are "protected" with DRM, thus cannot be used in iMovie. Downloading Apple Music Songs to iTunes will not remove the DRM protection. Songs purchased from iTunes after year 2009 generally do not carry DRM protection, and can be used in iMovie. You can just drag the song into the audio well of the timeline of an iMovie project. Or access the song fro the iMovie media sidebar of an iMovie project.

If the above does not describe your situation, then you can post back with more details of what you mean.

-- Rich

What do you mean by "a movie with permissions"? I don't think I have ever heard that term used before in this context.

-- Rich