May 18, 202011:40 AM - edited May 18, 202011:41 AM
Do you need each of the family members to be created as separate contact records, or would you be open to storing information for family members as custom properties on a single contact? HubSpot forms are generally designed to collect information for a single contact, although it's theoretically possible to trigger the creation of multiple contacts if multiple calls are made to the Forms API or Contacts API.
If you don't want to pursue a solution using APIs, it would be necessary to create a separate HubSpot form for each family member in order to create a new contact.
You can set up a password protected landing page (or landing pages) if you have a Marketing Hub Professional or CMS Hub Professional subscription. See this documentation for more detail.
It's against our terms of service to store sensitive information such as passport numbers, as outlined here. I'm not aware of any specific integrations or apps that integrate with HubSpot to allow the storage of this type of information, as the CRM isn't designed to handle this type of data.