curl --request GET \
  --url https://api.hubapi.com/email/public/v1/campaigns/{campaign_id}

{
  "appId": 123,
  "appName": "<string>",
  "contentId": 123,
  "counters": {
    "delivered": 123,
    "open": 123,
    "processed": 123,
    "sent": 123
  },
  "id": 123,
  "name": "<string>",
  "numIncluded": 123,
  "numQueued": 123,
  "subType": "<string>",
  "subject": "<string>",
  "type": "<string>"
}