Simple jQuery Cookie Pop-up - https://keithgreer.dev/simple-jquery-cookie-pop-up-notification-for-legacy-websites

pop-up.css

.eucookie-pop-up { display:none; position:fixed; z-index:9999; bottom:0; left:0; right:0; background:#dc143c; color:#fff; margin:1em; padding:0.5em; text-align:center; } 
.eucookie-pop-up .dismiss { float:right; width:7% text-align:center; padding-top:1em; } 
.eucookie-pop-up .dismiss a { color:#fff; cursor:pointer; font-weight:bold; font-size:150%; padding:1em; } 
.eucookie-pop-up .content { float:left; width:92%;  text-align:center;  } 
.eucookie-pop-up .content a { text-decoration: underline;color:#fff } 

pop-up.html

<div id="privacy-pop-up" class="eucookie-pop-up">
  <div class="dismiss">
    <a id="exit-popup">X</a>
  </div>
  <div class="content">
    <strong>Important information regarding cookies</strong><br>
    By using this website, you consent to the use of cookies in accordance with our
    <a href="https://example.com/privacy-policy-cookies">Privacy Policy</a>.
  </div>
</div>

pop-up.js

jQuery(document).ready(function() {
  
  if(localStorage.getItem('eucookie') != '123'){
    jQuery("#privacy-pop-up").delay(1).fadeIn(1000);
    localStorage.setItem('eucookie','123');
  } 
  
  jQuery('#exit-popup').click(function(e) { 
    jQuery('#privacy-pop-up').fadeOut(1000);
  });
  
});