dataLayer.push() data isn't shown in GTM preview

I am pushing my head against the wall with GTM setup. I am trying to pass custom event upon clicking a button but GTM preview shows no signs of this event being tracked.
I've added trigger by adding special action -> donate_button_click in GTM
Then in my HTML i am initialising datalayer with

<script>
    dataLayer = [];
</script>

Before the main GTM tag. After that i am trying to push my action in anchor tag by using

<a href="#XJKDHSTQ" style="display: none" onclick="dataLayer.push({'event':'donate_button_click'});"></a>

But GTM shows none of the events tracked.

Google Tag Manager (GTM) setup can sometimes be a bit tricky. Here are a few things you can check and possibly fix to troubleshoot this issue.

Order of scripts: Make sure the dataLayer script is placed above the Google Tag Manager container script in your HTML.

<script>
    window.dataLayer = window.dataLayer || [];
</script>
<!-- Google Tag Manager -->
<!-- ... -->
<!-- End Google Tag Manager -->

Syntax of dataLayer.push(): Make sure you are using the correct syntax. It looks correct in your example, but always double-check.

Ensure GTM Container is Installed Correctly: It's important to make sure that the Google Tag Manager snippet is installed correctly on your page. Verify it using Tag Assistant by Google or check the page source.

Check the 'Trigger' settings in GTM: Verify if the trigger is set correctly in GTM. The Event name in the trigger should exactly match the one you're pushing to the dataLayer. In your case, it should be 'donate_button_click'.

Visibility of the element: You have display: none on your anchor tag, which might prevent the button from being clicked and thereby the event from firing. Make sure the element is visible and clickable.

Use console logs for debugging: In your onclick event, you could add a console.log statement before the dataLayer.push() to verify that the click event is working. If the console log statement shows up in the browser's console, but the dataLayer.push() is still not working, then the issue is most likely with GTM or the dataLayer.push() statement.

<a href="#XJKDHSTQ" style="display: none" onclick="console.log('button clicked'); dataLayer.push({'event':'donate_button_click'});"></a>

Check in JavaScript console: Open your website and go to the JavaScript console in developer tools (right-click anywhere on the webpage and click inspect). Type dataLayer and hit enter. This will output the current state of dataLayer. Every time you click on the button, a new object should be added to this array. If it's not, there's something wrong with the way you're pushing events to the dataLayer.