To add testimonials your received using the Request URL on your website, you can simply navigate to Testimonials -> Embed and embed the code.
Note: You must have received at least 1 testimonial for the embed widget to work.
To see how it will look you can go to https://codepen.io/leemark/pen/ozyWbv and insert the code in the HTML box. You can adjust styling in the Styling tab.
To remove testimonials, you can go to the Workflow Tab, go to the Testimonial workflow, and move any testimonials you don't want to display to the Declined column.