Depends if you’re going through insurance or not. If you are, it’s best to call them and ask what the requirements are for coverage. I had an HMO, which required a referral from my listed PCP, as well as two letters from mental health professionals diagnosing me with gender dysphoria. If you have a specific surgeon in mind, you can always call and ask them about their policy.
If you need a referral then you probably need to figure out what providers your insurance accepts as ones that can refer you. Probably PP works? (I also suggest going surgeon researching on your own - you may be able to ask PP/whoever to refer you to someone specific). You can also get the referral during an annual checkup (it sounds like you may need to schedule one regardless if ur like me. Any dr that does them shld be able to refer you & count as a pcp for your insurance)