//* Add a button to display video (if present) in .entry-content-wrap
add_action( 'genesis_entry_footer', 'sk_add_video_btn' );
function sk_add_video_btn() {
        $video_url = get_post_meta( get_the_ID(), 'video_url', true );
        if ( $video_url ) {
                echo '<a href="'. $video_url .'" rel="nofollow">Click to watch the video</a>';
        }
}