There are two ways to create HubSpot leads from your Forethought widget.
1) Using Hubspot forms
You can use the existing Hubspot form that you have - get the form ID from HubSpot, and then navigate to action builder in the Forethought widget. Then create a new action that will make a POST call to the HubSpot form submission endpoint. After that, you’ll be able to use that action in your Forethought widget workflows.
This is a great option if your forms don’t have captcha protection or other reasons that would prevent proceeding with this approach.
2) Connecting Hubspot integration and using native lead creation
Unlike the first approach that uses the same form submission mechanism as the ones you put on your websites, this approach makes an authenticated call to HubSpot to create a lead, potentially allowing to set more values than existing forms you might have.
As the first step, navigate to intergrations page in Forethought dashboard and connect Hubspot. There you would see setup instructions - specifically you’ll need to create a private app in Hubspot, and provide the access token for that app in the integrations page.
Once you’ve done that, you will be able to use HubSpot Contact Creation action in Forethought widget. Typically, before that action you’d want to have forms to collect user info - names and emails at the very least (or these might be passed as inputs to the widget).
If you want to provide additional info, you can clone the default contact creation action, and configure an alternative one with whatever extra parameters you need in the body. From then on, save the updated action, and use it. See https://developers.hubspot.com/docs/api/crm/contacts for which fields can be updated - typically implementation engineer or developer involvement is expected if significant changes have to be made.