To make sure that only the right people can access your mockup, look at the top to see where the mockup will be stored when you click Create mockup:

• If your Private folder is open, your mockup will be saved in Private. This is the best option if you're not ready for other people to view, edit or import your mockup yet. You can then move it into a project when you're ready to collaborate.
• If your project folder is open, your mockup will be saved in this project. Everyone within the project will have permission to view, edit and import it as soon as you save it.
• If you create a mockup from the format or inspiration galleries, it will automatically be saved in Private.

Mockups are saved in the Business Manager account that you're using when you create a mockup, and can't be shared between accounts. Be careful that you are in the correct Business Manager account (and the correct ad account, if you have them). Ad accounts are sub-categories within a Business Manager account. For example, a marketing agency might have a Business Manager account for their business and ad accounts for all their clients. Learn more about Business Manager roles and permissions.

* Nguồn: Facebook