JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" name="" id="user" />

CSS

input {
    padding: 5px 8px;
    font-size: 15px;
    outline: none;
    color: #333;
}

JavaScript

$(function(){
    
    $("#user").keyup(function(event){
        if (event.altKey == false && event.ctrlKey == false)
            if ((event.keyCode >= 48 && event.keyCode <= 57 && event.shiftKey== false) ||
                (event.keyCode >= 65 && event.keyCode <= 90) ||
                (event.keyCode >= 97 && event.keyCode <= 122))
                alert("0-9, a-z or A-Z");
    });
});