If you tap My Music on the mashing screen and nothing happens, the first thing to check is the music library permission.
Check iOS Settings > 1SE > Media & Apple Music and make sure it is on. 1SE asks for this the first time you tap My Music ("Let 1SE access music library?"), and the button cannot open your library if that was declined.
If the permission is already on, make sure the Music app itself is still installed — your music library lives there, so deleting it leaves 1SE nothing to read. You can reinstall it here.