To save an image from a website, you can right click on it with a mouse and save it on your device. If you want to disable right click usage in your Berta.me website, you need to add a custom javascript code.

Navigate to Settings - Other settings panel and paste this piece of javascript code in field Javascript include.

<script>
window.addEvent('domready', function() {
    document.body.addEvent('contextmenu',function(e) {
        e.stop();
    });
});
</script>

Keep in mind that this is not a 100% safe protection, there are other ways how to copy your website's content.