Antonio Brown Fired Gunshots Outside Adin Ross Boxing Event, Zül-Qarnaįn Says

Zül-Qarnaįn Nantambu says he's the guy on video scuffling with Antonio Brown outside the Adin Ross boxing event in Miami ... and he claims Antonio went to grab a gun and shot at him. Zül-Qarnaįn tells TMZ ... AB squeezed off a couple shots…