If you have never "purchased" GarageBand before, the Cloud icon will not appear. You must first add the app to your Apple ID history using a device that supports iOS 17.
If you try to download GarageBand and receive an error saying it "Requires iOS 17.0 or later," use the following methods to trigger the "Download an older version" prompt. garageband ios 157 download link
While the official link remains the same for all versions, your device's compatibility determines which version is offered: How to Download GarageBand on iOS 15.7 If you have never "purchased" GarageBand before, the