Add the script to your page.
Let's see if we can help.
<script src="https://europe.banatic.com/banatic.js" defer></script>
Look for the head tags (<head> and </head>) in your HTML. Copy and paste the Banatic script in between the head tags just before the end </head> tag. Save your changes and publish your site. Thats it! Refresh your website and you are ready to go.