// Register oEmbed providers function flickr_oembed_provider() { wp_oembed_add_provider( '#https?://(www.)?flickr.com/photos/.*#i', 'https://www.flickr.com/services/oembed/', true ); wp_oembed_add_provider( '#https?://(www.)?flic.kr/p/.*#i', 'https://www.flickr.com/services/oembed/', true ); } add_action( 'init', 'flickr_oembed_provider' );