In order to add a lead form to your flipbook, when editing your flipbook, go to the Interactions tab and select the Form option.
Once clicked, a form will be added on the page you are viewing. If you want the form on a different page you will need to select that page first then add the form.
To customize the text on your lead form, simply click on the Edit button in the upper-left side of the editor.
A new panel will open where you can change the form's title, input placeholder and the text on the button.
The information that your readers insert in the form will be saved in a CSV file. You can download the CSV file by going to My flipbooks, clicking on the ... button in the upper-right corner of the flipbook in question and clicking on Stats.
On the Stats page, scroll all the way to the bottom and in the Leadform Stats section click on the Download CSV button.