When your webinar ends, you can take people automatically to different urls based on attendance.
So for example, if you want people attending the webinar to be redirected to a salespage, you can enter the url here.
If you want people who missed the webinar to be redirected to another page on your website, you can put that here.
If you do not configure these, they will just see the default completed webinar page until replay expires.
Then they will be redirected back to registration page.