Capea is a slang term that's the key to this whole song. The phrase no capea comes from the world of bullfighting, where a matador uses a cape (capa) to skillfully dodge a charging bull.
In this context, it means the girl isn't "taking the bait" or giving in to the singer's flashy attempts to win her over. When Xavi sings "la morrita no le capea," he's saying that despite all his money and gifts, the girl is expertly dodging his advances and isn't impressed.
Picture this: a guy tries every trick in the book to impress an unreachable girl at the club, and he fails every single time. In "No Capea," Mexican singer Xavi teams up with Grupo Frontera to talk about a stylish "niña fresa" [snobby, high-class girl] rocking Dior sneakers and carrying an expensive designer bag. People assume she has a sponsor paying her bills, but the truth is simpler: guys shoot their shot nonstop, and she just ignores them completely. In regional Mexican and urban slang, "no capea" means she isn't buying it; she refuses to fall for the game or give them any attention at all.
Xavi and Grupo Frontera roll out the heavy artillery anyway. They send over a massive "ramo buchón" [an enormous, flashy bouquet of flowers], dispatch a waiter with Dom Pérignon champagne, and even try picking up her tab. Her response? She won't let them pay, and whenever anyone walks up, she drops a flat "bye" and "se presea" [shows off or plays hard to get]. It is hilarious because the singer knows his own flaws, pleading, "Sé que tengo cara de bandido, pero, mami, aquí no corres peligro" [I know I look like a rogue, but, girl, you're in no danger here]. He promises he has no problem spending cash, using the phrase "tronar la liga" [literally "snap the rubber band," meaning stretching his wallet to spend big money]. Still, no matter how many trips to Dubai he offers, the princess leaves him empty-handed.