JSFiddle - React, Tailwind, and code Playground

HTML

<label for="input">Type something</label>
<input id="input" name="vorname" type="text" size="30" maxlength="30">

JavaScript

$.fn.delayKeyup = function(callback, ms){
     var timer = 0;
     var el = $(this);
     $(this).keyup(function(){                   
         clearTimeout (timer);
         timer = setTimeout(function(){
             callback(el)
                 }, ms);
     });
     return $(this);
 };

$('#input').delayKeyup(function(el){
        alert(el.val());
},1000);