wp_embed_excerpt_more( string $more_string )

Source

File: wp-includes/embed.php

function wp_embed_excerpt_more( $more_string ) {
	if ( ! is_embed() ) {
		return $more_string;
	}

	$link = sprintf(
		'<a href="%1$s" class="wp-embed-more" target="_top">%2$s</a>',
		esc_url( get_permalink() ),
		/* translators: %s: Post title. */
		sprintf( __( 'Continue reading %s' ), '<span class="screen-reader-text">' . get_the_title() . '</span>' )
	);
	return ' &hellip; ' . $link;
}