Simplest way

Insert this code to the head section of your document.

<script>
  !function(e,n,t,o,c,a,i){
    e.CookiePanelObject=c,e[c]=e[c]||function(){ (e[c].q=e[c].q||[]).push(arguments) },
    e[c].l=1*new Date,a=n.createElement(t),
    i=n.getElementsByTagName(t)[0],a.src=o,i.parentNode.insertBefore(a,i)
  }(window,document,'script','//cdn.pecha.pro/cookieLaw/latest.min.js','cookiePanel');
  cookiePanel('This page stores cookie. For more information click <a href="https://www.yourweb.com/page-about-cookies/">here</a>', 'I understand');
</script>