reading this: https://developers.google.com/tag-manager/devguide
I see you should put it before the tag manager, right?
So, complete the code above to make it appear something like:
add_action('__before_header','my_google_tag_manager', 0);
function my_google_tag_manager() {
?>
YOUR GOOGLE DATA LAYER CODE HERE
(looks like <script type="text/javascript">.....</script> )
YOUR GOOGLE TAG MANAGER CODE HERE
(looks like <script type="text/javascript">.....</script> )
<?php
}
Then, also in that link you can see it’s dataLayer
and not DataLayer
, but oh well maybe it was just an example to let me understand ??
Hopet this helps.