Last November, Jordyn Williams posted a TikTok of an original dance set to a song called “No Love” by J.K. Mac. The 19-year-old from Birmingham, Ala., thus inadvertently set off a dance challenge that came to be named, for that song, the #NoLoveChallenge.But as her dance became more popular, she began to notice that many of the videos failed to credit her TikTok handle for originating the dance.