curl --request GET \
  --url https://api.hubapi.com/crm-objects/v1/change-log/tickets

[
  {
    "timestamp": 1525297495553,
    "changeType": "CHANGED",
    "objectId": 176602,
    "changes": {
      "changedProperties": [
        "hs_lastmodifieddate",
        "content",
        "status"
      ],
      "newAssociations": [],
      "removedAssociations": [],
      "newListMemberships": [],
      "removedListMemberships": []
    }
  },
  {
    "timestamp": 1525297514887,
    "changeType": "CHANGED",
    "objectId": 176602,
    "changes": {
      "changedProperties": [
        "hs_lastmodifieddate",
        "content",
        "status"
      ],
      "newAssociations": [],
      "removedAssociations": [],
      "newListMemberships": [],
      "removedListMemberships": []
    }
  },
  {
    "timestamp": 1525298220133,
    "changeType": "CHANGED",
    "objectId": 194042,
    "changes": {
      "changedProperties": [
        "hs_lastmodifieddate",
        "subject",
        "created_by"
      ],
      "newAssociations": [],
      "removedAssociations": [],
      "newListMemberships": [],
      "removedListMemberships": []
    }
  },
  {
    "timestamp": 1525298357009,
    "changeType": "CREATED",
    "objectId": 217650,
    "changes": {
      "changedProperties": [
        "hs_lastmodifieddate",
        "subject",
        "createdate",
        "source_type",
        "created_by",
        "content",
        "status"
      ],
      "newAssociations": [],
      "removedAssociations": [],
      "newListMemberships": [],
      "removedListMemberships": []
    }
  }
]