Training a puppy to sit

Hi, everyone! My puppy, is reaching four months old and I have tried to teach her tricks with the Woofz app. Right now I am trying to teach her the sit command but everytime I want to get her attention, with or without treats, she naturally sits and stares at me. (Goal achieved I guess? Lol. So I don't know how I should use the command now. Should I just say sit and keep giving her treats as she is seated?