Send form submission data to HubSpot. Form submissions from external sources can be made to any registered HubSpot form. You can see a list of forms on your portal by going to the Contacts > Forms page
The Form GUID can be found in one of two ways. First, you can pull a list of Contact Forms using the Forms API, as documented here
You can also find the Form GUID in the HubSpot UI: navigate to Contacts > Forms from the navigation menu > click to edit a specifc form > when editing a specific form, you can find the Form GUID in the URL. In the URL https://app.hubspot.com/forms/62515/78c2891f-ebdd-44c0-bd94-15c012bbbfbf/edit/, the form GUID is 78c2891f-ebdd-44c0-bd94-15c012bbbfbf
Please Note You should also note that the HS Context and HubSpot tracking cookie listed as optional parameters are very important to users - they provide additional context about the form submission and the user submitting the form. While optional, you should pass these parameters in whenever possible for the best customer experience.