var modal = $('#modal');
$(document).ready(function() {
setTimeout(function(){
lity(modal);
}, 3000);
});
<div id="modal" class="modal" tabindex="-1" role="dialog">
<div class="modal__container" role="document">
<div class="modal__col">
<div class="box">
<h2 class="modal__title font-display-2 text-blue">Welcome to our new site!</h2>
<button class="modal__button button button--blue">Contact Us</button>
</div>
</div>
</div>
</div>