The form on the Contact tab of the Navu Sidebar can be configured to push the form details into a CRM. To enable this for HubSpot and Salesforce enable the HubSpot integration or the Salesforce integration. Enabling these automatically creates a corresponding form in these CRMs to capture the form details.
To push form fill details to Marketo does not depend on an integration with Navu but instead requires you create a form in Marketon and add the relevant details in the Navu portal. You can find Marketo form setup instructions here.
You can also add additional fields to the form in the Contact tab, you can see instructions for how to do that here.
