JSFiddle - React, Tailwind, and code Playground

HTML

<div class="access othertab" id="roomopts-access">
       <h1>Sicurezza</h1>
       <p>Qui puoi decidere la modalitĂ  di accesso alla stanza, proteggendola da eventuali visitatori indesiderati.</p>
        <br />
    <input type="radio" name="roomdoor" id="open" class="radio" checked/>
       <label for="open" class="radio-label">Aperta</label>
        <br />
       <input type="radio" name="roomdoor" id="doorbell" class="radio" />
       <label for="doorbell" class="radio-label">Chiusa a chiave (Campanello)</label>
        <br /> 
       <input type="radio" name="roomdoor" id="password" class="radio checkdisplay" />
       <label for="password" class="radio-label">Lucchetto (Password)</label>
         
       <div class="roompass todisplay">
       <label>Password stanza <span class="little">(solo se selezioni "Lucchetto")</span>
       <input type="text" id="roompass" />
       </label>
         
       <label>Ripeti password
       <input type="text" id="roompass" />
       </label>
       </div>
</div>

CSS

.access .roompass {
    display: none;
}

JavaScript

$(document).ready(function(){
    $('.radio').change(function(){
        if($(this).hasClass('checkdisplay') && this.checked)
            $('.todisplay').fadeIn('slow');
        else
            $('.todisplay').fadeOut('slow');
    });
});