The success message is the message that is displayed to the user when the form has been successfully submitted. To change it open process.php and search for the term
$config['successMessage'], it’s right at the top of the file. Change the success message to suit, you can add or remove as much HTML or text as you want there. Since the string is enclosed in single quotes
', if you want to include a single quote in your text or HTML you will need to escape it, by adding a backslash before it e.g.
Using form submitted data in the success message
You can also put submitted form data into the success message, such as the persons name. To do that just include the unique element name surrounded by percentage signs. For example to have a message containing the person’s name: