I'm looking to integrate my Web Form to HubSpot using the API recommended in https://legacydocs.hubspot.com/docs/methods/forms/submit_form It works well But the biggest drawback of this API is that there is NO AUTHENTICATION Anyone who knows or intercepts the API call from the Website will find out the Portal ID & Form Guid and can flood my hubspot instance with lot of Form Submissions.
Noticed this too, luckily, no spam yet. But I think another thing is related to this... form API requests are not logged. We're just debugging some issues and log would really help, but I guess, since API key is not needed (although used like docs say) it is not logged.