About dom events

I’m using Contact form7 Version 4.6 with wordpress 4.7

I tried your simple code example below but it seems to not recognize cf7 dom events like wpcf7submit and wpcf7mailsent

document.addEventListener( 'wpcf7submit', function( event ) {
  alert( "Fire!" );
}, false );

Dom event work with other events

<script>
	//var wpcf7Elm = document.querySelector( '.wpcf7' );
 
	document.addEventListener( 'keypress', function( event ) {
  	console.log( "Fire!" );
	}, false );
	
	</script>

Please can you tell me if there is a problem of version (doesn’t support cf7 dom events) or the problem is with the code !!