JSFiddle - React, Tailwind, and code Playground
HTML
<p><a href="#!/" id="lnk_add_sit">Show/Hide</a><p>
<input name="situacao" class="add_sit" style="display: none">
JavaScript
$('#lnk_add_sit').css('cursor', 'pointer').click(function(e) {
$('.add_sit').animate({
width: 'toggle'
}, 'fast');
});