Red Error to submit form

Hi,

We are having problems to use the component Contact form 7, in our contact form.
Always when we try to submit a message we receive the message, “There was an error trying to send your message. Please try again later.”, in red.

Can you help us, how to resolve this problem?

Versions we are using
PHP: 7.0.33
WordPress: 5.9.2
Avada: 7.6.1
Contact Form7: 5.5.6

Best regards

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