curl --request GET \
  --url https://app.herondata.io/api/email_templates \
  --header 'x-api-key: <api-key>'

{
  "rules": [
    {
      "cc_address": null,
      "heron_id": "<string>",
      "html_body": "<string>",
      "name": "<string>",
      "reply_to_address": null,
      "to_address": null
    }
  ]
}