Implementing custom widgets in an Angular application.

I've been following the documentation for creating surveys in an Angular application and everything's been working fine. However, I need a "star rating" type of question and noticed that it's provided in the "Custom Widgets" section of your documentation (specifically under barrating). I'm following the code and doing exactly as its shown on the page. I also downloaded the "surveyjs-widgets" library and it still isn't working. I'm stuck and haven't been able to find any solutions elsewhere. Any help would be great, thanks!