Email Sent Status Response

Contact Form 7 is functioning fine but “Additional Settings” warns that the code snippet here: on_sent_ok: “location.replace(‘/thank-you/’);” is depricated and will be dropped at the end of 2017.

So I’ve read over the relevant replacement script on this page: https://contactform7.com/dom-events/

…and copying the example literally as follows:
var wpcf7Elm = document.querySelector( ‘.wpcf7’ );

wpcf7Elm.addEventListener( ‘wpcf7submit’, function( event ) {
alert( “Fire!” );
}, false );

I do not get an alert. “Processing” shows at page bottom, the email is sent, and there is no end-user feedback at all.

I’ve also tried dom.addEventListener and had no luck there.

I’m not sure if this code is intended to be added to the contact page but a source code inspection does not show it there.

Any help appreciated.

Sam