wordpress主题Enfold中联系人提交按钮的自定义事件标记

I'd like to add a custom event tag for my contact submit button in wordpress theme Enfold. Editing functions.php file in wordpress. My faulty code. my thought process explained below:

    add_filter('avf_contact_form_submit_button_attr','avia_add_submit_attributes_to_cf', 10, 3);
function avia_add_submit_attributes_to_cf($att, $formID, $form_params){
  $att = "onclick="dataLayer.push({'event': 'button-click'});"";
  return $att;
}

It gives me the error "real 569" and syntax error, unexpected 'dataLayer' (T_STRING).

I took the base code from the developers official page https://kriesi.at/documentation/enfold/contact-form/#toggle-id-8-closed Under the "Add on click event to the contact form submit button " section. Default code:

add_filter('avf_contact_form_submit_button_attr','avia_add_submit_attributes_to_cf', 10, 3);
function avia_add_submit_attributes_to_cf($att, $formID, $form_params){
  $att = "onclick="_gaq.push(['_trackPageview', '/VP/XXX/XXX']);"";
  return $att;
}

It also had a Note – you will need to replace onclick=”_gaq.push([‘_trackPageview’, ‘/VP/XXX/XXX’]);” with your tracking code – it’s just an example. The $formID and $form_params variables contain some information about the contact form (settings, element id, etc.). These variables are useful if you want to set different attributes for different contact forms.

I've also replaced onclick=”_gaq.push([‘_trackPageview’, ‘/VP/XXX/XXX’]);” with my code sample from google https://support.google.com/tagmanager/answer/7679219?hl=en:

<a href="#" name="button1" onclick="dataLayer.push({'event': 'button1-click'});">Button 1</a>

What should I change in my code and how could I implement the name="button1" string into my code? Is it in the $formID?