curl --request GET \
  --url https://api.hubapi.com/automation/v4/flows/email-campaigns \
  --header 'Authorization: Bearer <token>'

{
  "paging": {
    "next": {
      "link": "",
      "after": ""
    },
    "prev": {
      "before": "",
      "link": ""
    }
  },
  "results": [
    {
      "emailContentId": "<string>",
      "emailCampaignId": "<string>",
      "flowId": "<string>"
    }
  ]
}