You can automatically send participants to a specific website, such as your home page, a thank-you page, or an external survey, once they complete their tasks and the wrap-up survey.
This setting is found in the Post-test (Step 4) configuration screen. Check the box labeled "Add a redirect link to show testers when they finish." You can then enter the Link text (the button label the participant sees) and the Link URL where they will be sent upon clicking.