JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="myText">

JavaScript

function removeNotAllowedChars($input) {
   $input.val($input.val().replace(/[^0-9]/g, ''));
}

$('#myText')
 .keyup(function() {
    var $input = $(this);
    removeNotAllowedChars($input);
 })
  .change(function() {
      var $input = $(this);
      removeNotAllowedChars($input);
  });