Adding hreflang tags automatically in WordPress subdirectory multisite

function mm_add_hreflang_attribute() {
    if (!( is_singular( 'locations' ) ) ) {
        $sites = array(
            array('', 'x-default'),
            array('en-gb/', 'en-gb'),
            array('en-au/', 'en-au'),
        );
        
        if ( is_post_type_archive('locations') ) {
            foreach ( $sites as $site ) {
                $site_url = network_site_url();
                $page_path = 'locations/';
                $geo_url = $site[0];
                $hreflang = $site[1];
                $url = $site_url . $geo_url . $page_path;
                echo '<link rel="alternate" href="' . $url . '" hreflang="' . $hreflang . '" />'. PHP_EOL;
            }
        } else {
            foreach ( $sites as $site ) {
                $site_url = network_site_url();
                $page_path = substr(get_permalink(), strlen(home_url('/')));
                $geo_url = $site[0];
                $hreflang = $site[1];
                $url = $site_url . $geo_url . $page_path;
                echo '<link rel="alternate" href="' . $url . '" hreflang="' . $hreflang . '" />'. PHP_EOL;
            }
        }
    }
}
add_action('wp_head', 'mm_add_hreflang_attribute', 1);

function mm_add_hreflang_attribute() {
if (!( is_singular( 'locations' ) ) ) {
    $sites = array(
        array('', 'x-default'),
        array('en-gb/', 'en-gb'),
        array('en-au/', 'en-au'),
    );
    
    if ( is_post_type_archive('locations') ) {
        foreach ( $sites as $site ) {
            $site_url = network_site_url();
            $page_path = 'locations/';
            $geo_url = $site[0];
            $hreflang = $site[1];
            $url = $site_url . $geo_url . $page_path;
            echo '<link rel="alternate" href="' . $url . '" hreflang="' . $hreflang . '" />'. PHP_EOL;
        }
    } 
else 
{
 foreach ( $sites as $site ) {
    $site_url = network_site_url();
    $page_path = substr(get_permalink(), strlen(home_url('/')));
    $geo_url = $site[0];
    $hreflang = $site[1];
    $url = $site_url . $geo_url . $page_path;
    echo '<link rel="alternate" href="' . $url . '" hreflang="' . $hreflang . '" />'. PHP_EOL;
    }
   }
  }
}
add_action('wp_head', 'mm_add_hreflang_attribute', 1);