This is how the default thank-you looks like

However, if you don't like Leonardo 🤪, or want to change the thank-you message, you can do it here. Just click the Thank you page button, which you can find it beneath the live preview card:

Then you should see a view like this 👇

In order to update the default thank-you image, simply choose an image to upload; you can see a live preview on the left:

If you don't want to show a thank-you image, you can check the box to hide the image: