JSFiddle - React, Tailwind, and code Playground

HTML

<textarea class="onlyNumbers" rows="4" cols="50"></textarea>

CSS

.onlyNumbers{
    border:1px solid #555555;
    border-radius:3px;
    width:100px;
    padding:5px;
    color:#888888;
    margin:20px;
}

JavaScript

$(document).ready(function(){

        $(".onlyNumbers").keydown(function(event) {
        
        if ( event.keyCode == 46 || event.keyCode == 8 || event.keyCode == 9 || event.keyCode == 27 || event.keyCode == 13 || (event.keyCode == 65 && event.ctrlKey === true) || (event.keyCode >= 35 && event.keyCode <= 39)) {
            return;
        }
        else {
        
            if (event.shiftKey || (event.keyCode < 48 || event.keyCode > 57) && (event.keyCode < 96 || event.keyCode > 105 )) {
                event.preventDefault();
            }
        }
    }); 

});