JSFiddle - React, Tailwind, and code Playground

HTML

<div class="testimonial" data-index="1">
    Testimonial 1
</div>
<div class="testimonial" data-index="2">
    Testimonial 2
</div>
<div class="testimonial" data-index="3">
    Testimonial 3
</div>
<div class="testimonial" data-index="4">
    Testimonial 4
</div>
<div class="testimonial" data-index="5">
    Testimonial 5
</div>

JavaScript

$('div[class="testimonial"]').each(function(index,item){
    if(parseInt($(item).data('index'))>2){
        $(item).html('Testimonial '+(index+1)+' by each loop');
    }
});