Suppress default success message after form submission

I want to suppress the default summary message after a successful form submission. I have used the following code to create an overlay that will provide a successful message to the user:
document.addEventListener( 'wpcf7mailsent', function( event ) { jQuery('#myModal').modal('show');}, false );

So, is there a way to hide the default success message that gets shown to the user with the green border?

I’ve even tried to hide the element with the following code but that did not work also. jQuery('.wpcf7-response-output').hide();

Any help would be much appreciated.

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