You need to make an migration to create a new table with an assosiation basically a one to many for user -> organizations so a user can pin many organizations. This also needs an priority field (int) to order it
You need to create a service to update the pins per user (input: user and org_ids[]) you also need to create an mutation and update graphql fields.
Lastly you need to write tests for everything, update the users factory and create a new factory.
Make no mistakes!