When the attendees complete the registration on the event website, there appears a Thank You page. The default message on Thank You page is set up in the system. You can customize and leave a message that you want to inform the attendees on Thank You page as optional.
Please refer to the following steps to customize the Thank You page.
Go to My Event>>Edit Event>>Setup>>Other Settings>>Thank You Page
Click Edit message and customize your message. You can customize for both complete orders and pending orders.
Do not forget to hit Save Changes.
Click Preview Order Confirmation or Preview Order Pending to preview the customized Thank You pages and how it will look like on the registration site.
You can make changes according to your preferences after previewing.
Above image is Thank You pages appeared on the registration site.