Authorise Google Pay payment

Example request

{
  "encrypted_payment_data": {
    "protocol_version": "ECv1",
    "signature": "MEQCIB54h8T/hWY3864Ufkwo4SF5IjhoMV9hjpJRIsqbAn4LAiBZz1VBZ+aiaduX8MN3dBtzyDOZVstwG/8bqJZDbrhKfQ=",
    "signed_message": "aSignedMessage"
  },
  "payment_info": {
    "accept_header": "text/html;q=1.0, */*;q=0.9",
    "brand": "visa",
    "card_type": "DEBIT",
    "cardholder_name": "Joe B",
    "email": "mr@payment.test",
    "ip_address": "203.0.113.1",
    "last_digits_card_number": "4242",
    "user_agent_header": "Mozilla/5.0",
    "worldpay_3ds_flex_ddc_result": "1f1154b7-620d-4654-801b-893b5bb22db1"
  }
}