curl --request GET \
  --url https://api.hubapi.com/integrators/timeline/v3/events/{eventTemplateId}/{eventId} \
  --header 'Authorization: Bearer <token>'

{
  "eventTemplateId": "<string>",
  "id": "<string>",
  "objectType": "<string>",
  "tokens": {},
  "createdAt": "2023-11-07T05:31:56Z",
  "customObjectTypeId": "<string>",
  "domain": "<string>",
  "email": "<string>",
  "extraData": {},
  "objectId": "<string>",
  "timelineIFrame": {
    "headerLabel": "<string>",
    "height": 123,
    "linkLabel": "<string>",
    "url": "<string>",
    "width": 123
  },
  "timestamp": "2023-11-07T05:31:56Z",
  "utk": "<string>"
}