curl --request GET \
  --url https://api.useduro.com/portal/email/subscriptions \
  --header 'x-portal-session: <api-key>'

{
  "merchants": [
    {
      "tenantId": "<string>",
      "merchantName": "<string>",
      "subscriptions": [
        {
          "id": "<string>",
          "status": "<string>",
          "cancelAtPeriodEnd": true,
          "currentPeriodEnd": "<string>",
          "plan": {
            "id": "<string>",
            "name": "<string>",
            "amount": 123,
            "currency": "<string>",
            "interval": "<string>",
            "intervalCount": 123
          }
        }
      ]
    }
  ]
}