There is no option for jQuery UI in the \"Frameworks & Extensions\" part. Should i add it as an external resource?
Under External Resources > click the text field and enter the url for a hosted jQuery library such as this one from google: https://ajax.googleapis.com/ajax/libs/jquery/2.2.2/jquery.min.js. Then click the plus icon.
https://ajax.googleapis.com/ajax/libs/jquery/2.2.2/jquery.min.js