wp_embed_excerpt_more

 * Filters the string in the 'more' link displayed after a trimmed excerpt.
 *
 * Replaces '[...]' (appended to automatically generated excerpts) with an
 * ellipsis and a "Continue reading" link in the embed template.
 *
 * @since 4.4.0
 *
 * @param string $more_string Default 'more' string.
 * @return string 'Continue reading' link prepended with an ellipsis.
 */
function wp_embed_excerpt_more( $more_string ) {
	if ( ! is_embed() ) {
		return $more_string;