Question regarding app offer: Buy $25 in gift cards and get a 6’ Spread Subway® cheer this holiday.

Hey guys, the Subways App has an offer: “Buy $25 in gift cards and get a 6' Spread Subway® cheer this holiday season. For every $25 in gift cards purchased, you'll get a free 6" sub on your next purchase.”

Does anyone know if the free sub is redeemable at any Subways location or does it depend on whether the specific Subways location is participating in the “promotion”?

Thanks in advance!