How NOT to get the featured thumbnail src of a WP Post....

snippet.php

<?php
            // Featured Image for FB Like
            $featured_image = get_the_post_thumbnail($post->ID);
            
            // Get image source
            if($featured_image) {
                $doc = new DOMDocument();
                $doc->loadHTML($featured_image);
                $imageTags = $doc->getElementsByTagName('img');
                
                foreach($imageTags as $tag) {
                    $image_url = $tag->getAttribute('src');
                }
            }				
            ?>