When a Geodir cpt has no featured image, try to add the og:image meta tag if the cpt has a default image

add_filter( 'geodir_details_facebook_og', function( $fcb_og, $post ) {
    if (
        ! empty( $fcb_og ) ||
        ! isset( $post->post_type ) ||
        ! is_singular( geodir_get_posttypes() )
    ) {
        return $fcb_og;
    }

    $post_type_obj = geodir_post_type_object( $post->post_type );

    if ( empty( $post_type_obj->default_image ) ) return $fcb_og;

    $url = wp_get_attachment_url( $post_type_obj->default_image );
    return $url ? '<meta property="og:image" content="' . esc_url_raw( $url ) . '"/>' : $fcb_og;
}, 99, 2 );