If I buy a ticket on the official website, I pick up the tickets at the club or elsewhere? Because says that I pick up in the modality "will call", but, where is the "will call"?

At the club. There's a person at the door with a list.

We just ordered them online & gave our name upon arrival at the front door & it was fine.

BTW, Just so you know, that's the definition of "will call". :-)

I didn't get my ticket online, but on the door for the following night. I suspect you would pick them up at the club but you should check with Birdland beforehand.

Inside the club.