Onsubmit event

Hello, I trying to figure out how to track submitted contact forms by Yandex Metrika. Before everything worked smooth via on_submit:, but as this option is discontinued I trying to make things work by wpcf7mailsent event.

So I came up with this code:

<script>
document.addEventListener( 'wpcf7mailsent', function( event ) {
  yaCounter00000.reachGoal('request');
}, false );
</script>

And it doesn’t work? Can you tell me why?

Thanks