The file
The song about never growing up was written by an agency team that included James Patterson, before he was the best-selling author on earth. It ran, in one version or another, for the rest of the chain's life.
When the stores closed in 2018 the jingle got a funeral's worth of coverage, and adults sang it in empty parking lots. The Retro Graveyard has the store; this file has the song.
Sources: Wikipedia — Toys "R" Us