JSFiddle - React, Tailwind, and code Playground

HTML

<input class="input" maxlength="1" id="text" type="text" autocomplete="off" />

JavaScript

var text = document.getElementById('text');
text.onkeypress = checkInput;
text.onpaste = checkInput;

function checkInput(e) {
    var e = e || event,
    char = e.type == 'keypress' 
        ? String.fromCharCode(e.keyCode || e.which) 
        : (e.clipboardData || window.clipboardData).getData('Text');
    if (/[^\d]/gi.test(char)) {
        return false;
    }
}