After further investigation, it seems there might be an alternative solution using HubSpot workflows. We could set up a daily workflow that fetches the invoice status from the external system and checks only invoices in Hubspot with the criteria “Open” invoice status. The workflow would run multiple times per day, allowing us to update the invoice status based on the external data.
However, this daily scheduling is not for free.
If anyone else has had experience with this approach or an alternative solution, please feel free to share!