JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id ="txtClient" value="aaaa" />

JavaScript

$('[id$=txtClient]').keypress(function (e) {
    //if is not a left or right arrow key
		console.log(e.which);
      if (String.fromCharCode(e.which) == '#'){
            e.preventDefault();
        }
});