Create a referral

    A referral can only be accessed by the user who created it.
    Use this endpoint to create a referral linked to the access_token's user.
    Required fields to create a referral:
      - patient's first_name, last_name, email, phone, date_of_birth_iso, gender,
        address_line_1, and address_postcode
    More information must be entered before submitting or confirming a referral.
    See the "Submit a referral" and "Confirm a referral" for more information.