JSFiddle - React, Tailwind, and code Playground

HTML

<div class="myselectorClass" data-multiselect="1" data-type="zusize" id=zusize>
    <ol>
        <li class="">2T</li>
        <li class="">3T</li>
    </ol>                   
</div>

CSS

.selected {
    color: red;
}

JavaScript

var selectorsList = $('.myselectorClass').find('li');
$(selectorsList).each(function(i,k){
    $(this).addClass('selected');
});