Introduction to myself on this website. I need to know how to enable each LLM (specifically Sonar Pro)

Hello! I would like to get started with this website’s search function. I already know how to ask questions and whatnot, but can someone tell me how I can enable each LLM (Sonar, Sonar Pro, Sonar Reasoning, Sonar Reasoning Pro, and Sonar Deep Research)? Thanks (I prefer Sonar Pro).