Returns the accountReference value for the Embedded Partner Merchant account created

{
  "source": "onboarding",
  "event": "onboardingSuccess",
  "date": 1684749021489,
  "dateFormatted": "2023-05-22T09:50:21.489833737Z",
  "data": {
    "emailAddress": "[email protected]",
    "externalId": "EmbeddedPartnerInternalId",
    "accountReference": "39bd9cd2-8d57-4547-ae2a-f82c5bc328ce"
  }
}