You will need to determine the source of the issue, and resolve that, before the Quiz can function. The best way to isolate issues like this is to disable your theme and plugins, and re-enable them one at a time, testing the site after each one to see when the issue occurs.
When you know what plugin or theme is creating this JS error, you can reach out to them for further support on the matter.
Once that JS errpr is resolved, other software that uses JS will be able run nornally, like quiz cat.
Hope that helps. let us know if we can be of further assistance.