JSFiddle - React, Tailwind, and code Playground

HTML

<input class="numbersOnly" id="n1" type="text" value="100"><br><br>
<input class="numbersOnly" id="n2" type="text" value="200">

CSS

body {padding:10px}

numbersOnly {padding:5px}

JavaScript

$(document).ready(function() {
    $('.numbersOnly').keyup(function () { 
        this.value = this.value.replace(/[^0-9\.]/g,'');
    });
});