The aim is simple, run the google tracking code AFTER the user has accepted and if the user do not accept, do not run.

I went with placing the code inside the tag, but I am struggling to understand how to incorporate a "dismiss" option as well.

This is my "work in progress" code as of right now:

<script>
(function() {
    if (!localStorage.getItem('cookieconsent')) {
        document.body.innerHTML += '\
        <div class="cookieconsent" style="position:fixed;padding:20px;left:0;bottom:0;background-color:#000;color:#FFF;text-align:center;width:100%;z-index:99999;">\
            This site uses standard cookies and Google Analytics. By clicking on "I understand", you agree to their use. \
            <a href="#" style="color:#CCCCCC;font-weight:bold;">I Understand</a>\
        </div>\
        ';
        document.querySelector('.cookieconsent a').onclick = function(e) {
            e.preventDefault();
            document.querySelector('.cookieconsent').style.display = 'none';
            localStorage.setItem('cookieconsent', true);
        };
    }
})();
</script>

And from what I understand, I need to place the google tracking after this line:

localStorage.setItem('cookieconsent', true);

But since the script tag is already opened, how do I do that?

Example of the tracking code:

<script async src="https://www.googletagmanager.com/gtag/js?id=G-XXXXXXX"></script>
<script>
window.dataLayer = window.dataLayer || [];
function gtag(){dataLayer.push(arguments);}
gtag('js', new Date());
gtag('config', 'G-XXXXXXXX');
</script>

On top of this, I'm not sure how to add a dismiss option so that the google code does not run. I'm grateful for all the input I can get.