How do I do "Codeless UI Theme"?

Hi, I have just downloaded the latest version of powerbuilder 2021.

From your own website https://www.appeon.com/products/powerbuilder/ui-modernization

It mentions how I can do 'Codeless UI Theme'.

Does this mean I create my own custom theme without having to code it? If so where would I go to do the custom themes?

I am using your example.