<form action="/.../.../#wpcf7-f1581-p853-o1" method="post" class="wpcf7-form" enctype="multipart/form-data" novalidate="novalidate">

var myEl = document.getElementsByClassName('wpcf7-submit');

myEl.addEventListener('click', function() {
    window.scrollTo({ top: 0, behavior: 'smooth' });
}, false);