GarageBand for Mac - getting ringtones made to your iPhone (workaround)
Described in this post is a way for a Mac user using GarageBand for Mac (version 10.2.0) to create a ringtone (per GarageBand for Mac: Share songs as ringtones ), but to then hand it to your iPhone (in this case using version 11.2.6), open it in GarageBand for iOS, and share the file to your set of ringtones.
1) Have your GarageBand for iOS app create a folder for its projects in iCloud Drive
2) Once you've followed how to create a ringtone-configured project in GarageBand for Mac, use the Share menu and select 'Project to GarageBand for iOS'
3) Save the project to the GarageBand for iOS folder you created earlier in Step 1.
4) Locate the file in GarageBand for iOS
5) Tap 'Select' in the upper right, and tap the song you want
6) Tap the Share button in the lower left and then tap 'Ringtone' (see below)
7) This will allow you to export the song
8) A dialog box will allow you to tap 'Use sound as...' to allow you to be specific.
9) Tapping 'Standard Ringtone' will activate the ringtone, making it the default ringtone.
10) To check to see if it made it, go to Settings > Sounds & Haptics and make sure the one you want is listed and checked.
11) Enjoy your new ringtone!
12) Go back to your Mac and make more, ya genius! 😎
GarageBand (Mac) '11, macOS High Sierra (10.13.3), GarageBand for iOS —version 11.2.6