Please watch GoDaddy's instructions here on how to embed JavaScript code on their website builder. Watch from minute 1:27.

To get the Callback Tracker widget code, login to your Callback Tracker account, navigate to 

Product & Services / Callback Widget / Websites / Code Embed

Copy the code and remove <noindex> in the beginning and </noindex> at the end of your widget code. 

Please embed widget code (from Code Embed tab) into the </body> section under GoDaddy website builder.

Click "OK" button at the end.