It’s both, it’s not just a Miami thing. I hear it all over Latin America. In both ways like dale dale Olimpia (go <team> go).

Me: I’ll have a burger. Waiter: dale.

I don’t hear it much in Argentina tho, but maybe I wasn’t listening for it.

Don't forget "vale" which I always think of as being Spain Spanish but you hear it all over the Spanish speaking world too. Which is like almost the same, but not the same.