Microsoft Whiteboard Migration and Inventory preparation

Hi All,

We are working in a tenant to tenant migration and It scoped for Microsoft Whiteboard Migration. Can anyone help me with below queries,

1. How can I collect all the whiteboards available in a tenant to get the Inventory.
2. Can I share whiteboard with external users ?
3. What is the best way to migrate Whiteboards from one Tenant to another ?
4. Where whiteboards are getting stored once we create it.

Thanks and Regards,

Hari