Use iCloud with GarageBand for iPad
In GarageBand for iPad, you can save your songs to iCloud Drive and then open them from other devices or other apps. You can also open songs stored in iCloud Drive and download them to your iPad.
When you close a song or close GarageBand, the song is updated with your latest changes in iCloud. If changes made on multiple devices are out of sync, a copy of the song with the newest changes is saved to the same location as the original in iCloud Drive.
Turn on iCloud for GarageBand
Before you can use iCloud Drive with GarageBand, you must set up iCloud in the Settings app on your iPad.
Close GarageBand for iPad.
On the Home screen, tap Settings, then tap your name at the top of the sidebar.
Tap iCloud on the right, tap Drive, then make sure “Sync this iPad” is turned on.
Tap Apps Syncing to iCloud Drive, then make sure the GarageBand switch is turned on.
You might have to scroll down to see the GarageBand icon.
For more information, see the iCloud Support website.
Upload a song to iCloud Drive
In the My Songs browser, touch and hold the song you want to upload, then tap Move.
Navigate to a save location in iCloud Drive, then tap Copy.
Copy a song from iCloud Drive to your iPad
In the My Songs browser, locate the GarageBand song in iCloud Drive you want to copy.
Touch and hold the song you want to copy, then tap Move.
Navigate to a save location on your iPad, then tap Copy.
Open a song from iCloud Drive
Songs available to download from iCloud Drive appear with an iCloud download badge 
.
In the My Songs browser, locate and tap the GarageBand song in iCloud Drive you want to open.
The song is downloaded. If there is a newer version in iCloud, the newer version is downloaded to your iPad. If the version on your iPad is newer, that version is uploaded to iCloud.
Create a song in iCloud Drive
In the My Songs browser, navigate to iCloud Drive, then locate and tap the GarageBand for iOS folder.
Do one of the following:
Tap the Add Song button
in the upper-right corner of the screen.Tap Create Song on the right.
The Sound browser opens, where you can choose a Touch Instrument to use in the song. When you close the song, the latest changes are saved to the original location in iCloud Drive.
Delete a song in iCloud Drive
When you delete a song in iCloud Drive, the song is deleted on all your devices.
In the My Songs browser, locate the GarageBand song in iCloud Drive you want to delete.
Touch and hold the song you want to delete, then tap Delete.
If you turn off iCloud for GarageBand, your songs stored in iCloud Drive will be deleted from your iPad but will remain stored in iCloud Drive. If you want to turn off iCloud and keep your songs on your iPad, you need to duplicate the songs you want to keep before you turn off iCloud.