The following page of the guide to LEGO Star Wars: The Skywalker Saga explains how to complete the Dance in the Cantina challenge on Tatooine.
The Dance in the Cantina challenge is unlocked by completing the Bab Bar Brawl side mission.
To complete the quest, you need to buy the rumor and activate the quest. Then visit the Mos Eisley Cantina on Tatooine and use the Force as a Jedi or Dark Side character to make 5 people dance. You can take control of people at the bar, as well as those marked on the minimap. This challenge needs to be performed quickly, as the people you've compelled to dance will eventually return to their normal activities.
You will receive 2 Kyber Bricks for completing the challenge.