Currently, there isn't a way to add a created property to the about card via API. As for the default properties, these are properties that are created by HubSpot and so it cannot be created via API/within your portal. That said, you can create custom contact properties.
Currently, there isn't a way to add a created property to the about card via API. As for the default properties, these are properties that are created by HubSpot and so it cannot be created via API/within your portal. That said, you can create custom contact properties.