How to set a music file as a Notification Tone on my Samsung Phone
Head into your Settings > Apps.
2 Tap on an app you would like to customise the Notification tone.
3 Tap on Notifications.
4 Select a category you would like to customise.
5 Ensure that you have selected Alert then tap on Sound.
6 Tap on a sound then press the back button to apply changes.
This page maybe helpfulhttps://www.samsung.com/au/support/mobile-devices/set-a-music-file-as-a-notification-tone/