This article explains how to customize page settings, including page size, and edit individual pages using the "Edit SVG" option in a template.
The following options can be set custom per page after clicking "Add Page". After saving the product, you will get two more buttons "Edit SVG" and "Delete Content".
When you click on the "Edit SVG" button, the designer will open and you can edit the page from the CUSTOM template. Make sure that you edit only one page of the template and not all of them. You will need to edit each page individually.
Unit
Here you can set the unit you want to use for the page size.
Width
Set the width of the page.
Height
Set the height of the page.
Options
Here you can change the name of the page you have set up above.