Custom Pages can be selected to enter source page code or they can be used right here from the pop up to drag & drop an HTML file to create a custom page. Custom Pages are added depending on the different HTML pages included in your downloaded template. For example, if you download an HTML template that has Home, Blog, Contact, and About HTML pages, you would + Add Page for each individual HTML page file and drop them into the blue rectangle displayed in the image below.

To learn more about how to use templates and custom pages with your Website Builder, please check out the Templates section of the support page. 

Please contact our customer support at [email protected] or by simply clicking the chat icon in the bottom right corner of the screen if you have any questions or issues