I am trying to do a mass enablement of a merchant ids for a psp. The ids have been approved by apple. I am attempting to add more using the Post Request: https://apple-pay-gateway.apple.com/paymentservices/registerMerchant
(https://developer.apple.com/documentation/applepaywebmerchantregistrationapi/register_merchant) but am always getting a Refuse to connect error.
What authentication is required to get a 200 successful response?