JSFiddle - React, Tailwind, and code Playground

HTML

<fieldset>
    <div class="alert forward"><span class="coming"><strong>NOTE:</strong></span> A maximum of 5 address book entries allowed.</div>
    <div class="leftAddress">Any1</div>
    <div class="alert forward"><span class="coming"><strong>NOTE:</strong></span> A maximum of 5 address book entries allowed.</div>
    <div class="leftAddress">Any2</div>
    <div class="leftAddress">
        <!--Insert-->
         <h3 class="addressBookDefaultName">Harry Testing</h3>

    </div>
    <div class="leftAddress">
        <!--Insert-->
         <h3 class="addressBookDefaultName">Heba ElZany</h3>

    </div>
    <div class="leftAddress">
        <!--Insert-->
         <h3 class="addressBookDefaultName">Yamen Shahin&nbsp;(primary address)</h3>

    </div>
    <div class="leftAddress">
        <!--Insert-->
         <h3 class="addressBookDefaultName">Yamen2 Shahin2</h3>

    </div>
    <div class="leftAddress">
        <!--Insert-->
         <h3 class="addressBookDefaultName">Yamen3 Shahin3</h3>

    </div>
</fieldset>

JavaScript

window.onload = function(){
    document.getElementsByClassName('leftAddress')[0].style.display = 'none';
}