You can respond to a submission event and change the page of the browser to a thank you page. This can be either another page of your website or can use your framework’s routing system if you are using a framework.
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap-icons/font/bootstrap-icons.css">
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap/dist/css/bootstrap.min.css">
<script src="https://cdn.form.io/js/formio.embed.js"></script>
<div id="formio"></div>
Formio.createForm(document.getElementById('formio'), 'https://examples.form.io/example')
.then(function(form) {
// What to do when the submit begins.
form.on('submitDone', function(submission) {
window.location = '/app/thanks.html';
});
});