Custom Cards.js - Cannot read property 'setConfig' of undefined

Hi, I am following the process for importing a .js file, then adding a resource URL in Lovelace, then adding the custom card code on a dashboard but get the error.

What is the format of the URL I should be entering if I am running HA within the network and not in a www folder like the link tells me to do.

Do I add anything to the config.yaml file, or just import the .js file into the Config folder, then use a custom card code?