What does your browser console say? (F12; Browser developer tools).
I believe there's a good chance that you need to provide an API token/key, which can be inserted in the widget configuration.
Maybe the widget is using a iframe. Please check the settings under the tab Network in your cloudnode:
Prevent embedding your app in an IFrame
Your application can be embedded in another site using an IFrame. To prevent this, you can deny embedding using the setting below. This will set an X-Frame-Options header for each HTTP response from your app. Please note that Chrome will ignore the "Allow from specific domain" option.