Why does a broken icon appear when I toggle a button?

[ductu3590]

In the instructions it says: You need to add www/loader.svg

However, the instructions do not say where to add it?

And let me ask, where can I see the list of icons? For example: icon_hue; icon_lamp ... I saw this code but don't know what other icons there are to change?

[ngocjohn]

www folder