Add page to already existing webform

I want to add a page to my already existing active webform. Therefore I have found a link with a tutorial.

https://helpx.adobe.com/in/sign/adv-user/web-form/edit.html

However, when I click on edit I always come directly to the 2nd page called "prepare" where I can adjust the fields that have to be filled in by the users of the webform. However, it does not take me to the "Add" page where I can add document pages. Does anyone know how to get to the first page? That would be really helpful