Some basics. This public HT site does not provide referrals/prescriptions/ notes or any other form of direct care. It is a public information forum. If you expect a 3rd party (insurance) to pay for any specialty care you need to contact them and find out who they would accept a referral from. Many only accept referrals from their own network physicians. If you're paying out of pocket refer yourself.
Not via this forum. One can go to see an Endocrinologist without referral unless one has a restrictive insurance plan such as an HMO or a POS plan that requires a referral. If one has a PPO plan, a referral is almost never needed unless one has a rare, restrictive PPO plan that requires a referral. For better insurance coverage (less out-of-pocket costs), consider seeing an in-network doctor.