There's a new version of the HubSpot API
As of November 30, 2022, HubSpot API Keys are being deprecated and are no longer supported. Continued use of HubSpot API Keys is a security risk to your account and data. Your API Keys could be deactivated at any time after Nov. 30th, and we recommend that you migrate to Private Apps as soon as possible so you do not lose business-critical functionality.
There's a new version of the Owners API. We've redesigned our owners API and it is out now in developer preview. Check out the new API
HubSpot uses owners to assign CRM object records (contacts, companies, deals, tickets, and engagements) to specific people in your organization.
Use case for this API: The Owners API can be used to get the IDs of the owners you have in HubSpot, allowing an integration to assign records.