How do I use my own music in LumaFusion?
You can use any music that isn't marked as 'protected' by Apple in your project.
You can use music from iTunes by tapping on the library category icon at the top left of the Library and select iTunes. You need to make sure the music is downloaded to the device from the Music App (unfortunately LumaFusion can't download it like it does for photos and videos). Once downloaded in the Music App, swipe down on the LumaFusion Library to update the Library and then your downloaded songs should appear if they are not protected.
Protected music can't be used by LumaFusion and so is not shown in the Library. This generally includes music that you paid $0.99 for in iTunes (rather than paying $1.29 for the higher bitrate and unprotected version). If you subscribe to Apple Music, make sure to download the songs you want to use, then you'll have to check whether they are protected. It depends upon the individual song.
Keep in mind that even music you have purchased will likely be flagged on sites like YouTube, Facebook, Vimeo etc, for copyright infringement so the practical use of your iTunes music could be limited.
You can also import music from cloud storage into LumaFusion. Tap on the ... button at the top left of the library, then tap on Import Media. You'll be able to select audio files(mp3 m4a, caf, aiff) files to import. These will appear in the Imported category in the library.
Finally, from other apps (GarageBand for example), you can select an audio file or music project, tap on the Share button, and select LumaFusion. The file will be opened in LumaFusion and added to the Imported category.