JSFiddle - React, Tailwind, and code Playground

HTML

<label>Bara siffror plz: 
    <input>
</label>

JavaScript

$('input').keydown(function (e) {
    //return e.which >= '0'.charCodeAt(0) && e.which <= '9'.charCodeAt(0);
    return e.which >= 48 && e.which <= 57;
});