Next FlipBook Maker uses Amazon Simple Storage Service (Amazon S3) to store your online flipbook. You can add password to control access to your flipbook.
Click Book Management on the flipbook maker interface to open below window:
Click the pencil icon. As you can see from below window, you can set your flipbook public or private.
Choose “Private” and enter email address. Readers will be asked to enter the same email address as you set when they want to read your flipbook.