We always want the name of the artist and song title that was actually featured in the show/movie to be listed.
In cases where that version is not currently available anywhere (unreleased), it can also be helpful to submit the original version of the song, with an indication in the scene description that it's the original version of the song that is actually featured.
To indicate that a cover version was used, enter the original song, and in the scene description field, note [Cover version].