Watch the video:
Timestamps:
0:00 - Explanation
0:13 - Find notification/ringtone Settings
0:34 - Make sure ringtone/notification is the right format
1:03 - Import custom MP3 ringtones/notification sounds
Want to use an MP3 as a ringtone or notification noise on Android, but can’t figure out how? This video shows you how to import custom sounds and use them on your phone, even when it’s not obvious where to put them.