Refreshing window after message sent

I’m using Contact Form 7 in a modal box (with Elementor Premium addons), and everything works as intended.
However, my client is requesting that after the user clicks on the “send” button ONLY the “thank you” message appears, without the (now) empty form.

In other words, I’d like to know ho to make the following happen:

1. user clicks on “contact” button
2. modal box with contact form opens
3. after user clicks “send” button the form is replaced by the “message sent successfully” box

many thanks

The page I need help with: [log in to see the link]