Start by calling the 888 number and speaking to the care logistics team. They will collect your medical history, discuss the reason for your call, and basically do everything that would happen in the office, right then over the phone.
Next, they will get a provider on the call with you. That provider will have all the information they need to potentially diagnose and prescribe while you are on the phone with them.
If you need to be seen in person, they will schedule the appointment for you and call ahead and provide the doctor with all the information so once you arrive.