If you would like to add a new page to your existing test it can be done so by clicking the 'Add section' in the box on the right-hand side. The newly created section will appear right below the one that was selected while adding the section. The sections are numbered for easy navigation.
The new section will appear after the currently selected section. If you want it to appear in a different order simply drag and drop the sections to the desired order.
To delete a page click on the button in the top right-hand corner of the section, then delete and confirm.