Hellish Rebuke as a racial spell, does this spell use up one of my spell slots?

@JeremyECrawford If I'm playing a Tiefling Bard, who knows Hellish Rebuke as a racial spell, does this spell use up one of my spell slots?

— moblin (@arcanacheck) April 17, 2017

Infernal Legacy gives a tiefling the ability to cast hellish rebuke once between long rests. It doesn't require a spell slot. #DnD https://t.co/NMpc8j7ziy

— Jeremy Crawford (@JeremyECrawford) April 17, 2017