JSFiddle - React, Tailwind, and code Playground

HTML

<table>
        <tr class="numberWithCommas">
            <td>5000</td>
            <td>5600</td>
        </tr>
    </table>

CSS

td {
    padding: 10px;
}

JavaScript

function numberWithCommas(x) {
        return x.toString().replace(/\B(?=(\d{3})+(?!\d))/g, ",");
    }
    
    var elements = document.querySelectorAll('.numberWithCommas td'),
        i;
    
    for (i in elements) {
        if (elements[i].innerHTML !== undefined) {
            elements[i].innerHTML = numberWithCommas(elements[i].innerHTML);
        }
    }