Hello Andrius, 

Yes, the first option would be setting Redirect URL in General settings of plugin, so when customers come to that Congratulations page they have Finish button, so when they click on it, they will be redirected to this URL.

But if the customers leave the page before and you want different solution, as you said, you can use hooks like beforeConfirmedBooking that will be triggered when your customers confirm booking. You can set the redirect URL that you need like on this script (we use https://www.google.com as an example, but you will replace this with the URL that you want)

<script>
window.beforeConfirmedBooking = function()
{
window.location.href = "https://www.google.com";
};
</script>

You should insert this script on the page where you have Amelia shortcode.

Hope this helps!

If you have any other questions or concerns feel free to ask, 

Hello Andrius, 

You are welcome!

Great, glad to hear it worked!

If you have any other questions or concerns feel free to open a new ticket and we will gladly help,