WP_Sitemaps::add_robots( string $output, bool $public )

Source

File: wp-includes/sitemaps/class-wp-sitemaps.php

public function add_robots( $output, $public ) {
		if ( $public ) {
			$output .= "\nSitemap: " . esc_url( $this->index->get_index_url() ) . "\n";
		}

		return $output;
	}