Google Analytics の Cookie をユーザーが同意した場合だけ書き出す方法

// obtain plugin
var cc = initCookieConsent();

// run plugin with your configuration
cc.run({
    current_lang: 'ja',
    autoclear_cookies: true,                   // default: false
    page_scripts: true,                        // default: false

    // mode: 'opt-in'                          // default: 'opt-in'; value: 'opt-in' or 'opt-out'
    // delay: 0,                               // default: 0
    // auto_language: null                     // default: null; could also be 'browser' or 'document'
    // autorun: true,                          // default: true
    // force_consent: false,                   // default: false
    // hide_from_bots: false,                  // default: false
    // remove_cookie_tables: false             // default: false
    // cookie_name: 'cc_cookie',               // default: 'cc_cookie'
    // cookie_expiration: 182,                 // default: 182 (days)
    // cookie_necessary_only_expiration: 182   // default: disabled
    // cookie_domain: location.hostname,       // default: current domain
    // cookie_path: '/',                       // default: root
    // cookie_same_site: 'Lax',                // default: 'Lax'
    // use_rfc_cookie: false,                  // default: false
    // revision: 0,                            // default: 0

    onFirstAction: function(user_preferences, cookie){
        // callback triggered only once
    },

    onAccept: function (cookie) {
        if(cc.allowedCategory('analytics')){
            gtag('consent', 'update', {
                'analytics_storage': 'granted'
            });
        }
    },

    onChange: function (cookie, changed_preferences) {
        if (cc.allowedCategory('analytics')) {
            gtag('consent', 'update', {
                'analytics_storage': 'granted'
            });
        }
        else {
            gtag('consent', 'update', {
                'analytics_storage': 'denied'
            });
        }
    },

    languages: {
        'ja': {
            consent_modal: {
                title: 'Cookieについて',
                description: 'Hi, this website uses essential cookies to ensure its proper operation and tracking cookies to understand how you interact with it. The latter will be set only after consent. <button type="button" data-cc="c-settings" class="cc-link">Let me choose</button>',
                primary_btn: {
                    text: 'Cookieを許可する',
                    role: 'accept_all'              // 'accept_selected' or 'accept_all'
                },
                secondary_btn: {
                    text: 'Cookieを拒否する',
                    role: 'accept_necessary'        // 'settings' or 'accept_necessary'
                }
            },
            settings_modal: {
                title: 'Cookieの設定',
                save_settings_btn: '設定を保存',
                accept_all_btn: 'すべて同意する',
                reject_all_btn: 'すべて拒否する',
                close_btn_label: 'Close',
                cookie_table_headers: [
                    {col1: 'Name'},
                    {col2: 'Domain'},
                    {col3: 'Expiration'},
                    {col4: 'Description'}
                ],
                blocks: [
                    {
                        title: 'Cookie usage 📢',
                        description: 'I use cookies to ensure the basic functionalities of the website and to enhance your online experience. You can choose for each category to opt-in/out whenever you want. For more details relative to cookies and other sensitive data, please read the full <a href="#" class="cc-link">privacy policy</a>.'
                    }, {
                        title: 'Strictly necessary cookies',
                        description: 'These cookies are essential for the proper functioning of my website. Without these cookies, the website would not work properly',
                        toggle: {
                            value: 'necessary',
                            enabled: true,
                            readonly: true          // cookie categories with readonly=true are all treated as "necessary cookies"
                        }
                    }, {
                        title: 'Performance and Analytics cookies',
                        description: 'These cookies allow the website to remember the choices you have made in the past',
                        toggle: {
                            value: 'analytics',     // your cookie category
                            enabled: false,
                            readonly: false
                        },
                        cookie_table: [             // list of all expected cookies
                            {
                                col1: '^_ga',       // match all cookies starting with "_ga"
                                col2: 'google.com',
                                col3: '2 years',
                                col4: 'description ...',
                                is_regex: true
                            },
                            {
                                col1: '_gid',
                                col2: 'google.com',
                                col3: '1 day',
                                col4: 'description ...',
                            }
                        ]
                    }, {
                        title: 'More information',
                        description: 'For any queries in relation to our policy on cookies and your choices, please <a class="cc-link" href="#yourcontactpage">contact us</a>.',
                    }
                ]
            }
        }
    }
});

<!DOCTYPE html>
<html lang="ja">
  <head>
    <meta charset="utf-8">

    <script>
      // Define dataLayer and the gtag function.
      window.dataLayer = window.dataLayer || [];
      function gtag(){dataLayer.push(arguments);}
      // Default ad_storage to 'denied'.
      gtag('consent', 'default', {
        //'ad_storage': 'denied',
        'analytics_storage': 'denied'
      });
    </script>

    <!-- Google Tag Manager -->
    <script>(function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-XXXXXXX');</script>
    <!-- End Google Tag Manager -->

    <!-- Cookie Consent -->
    <script defer src="js/cookieconsent.js"></script>
    <script defer src="js/cookieconsent-init.js"></script>
    <link rel="stylesheet" href="css/cookieconsent.css" type="text/css" media="screen">
    <!-- End Cookie Consent -->

    <title>Cookie Consent TEST</title>
  </head>
	
  <body>
    <!-- Google Tag Manager (noscript) -->
    <noscript><iframe src="https://www.googletagmanager.com/ns.html?id=GTM-XXXXXXX" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript>
    <!-- End Google Tag Manager (noscript) -->

    <p>Cookie Consent TEST</p>
    <button type="button" aria-label="Cookieの設定" data-cc="c-settings">Cookie Settings</button>
		
  </body>
</html>