AMP subscription form

amp_subscription_form.html

<form 
action-xhr="https://fabulousnewwebsite.com/scripts/subscriber_process.php"
verify-xhr="https://fabulousnewwebsite.com/scripts/subscriber_process.php"
method="post"
custom-validation-reporting="show-all-on-submit"
class="mb3"
>
<label class="center">
  Email:
  <input type="text"  
  name="subscriber_email" >
</label>
 <div class="center">
   <input type="submit" value="Subscribe!">
 </div>
    
    <div submit-error>
      <template type="amp-mustache">
        {{#verifyErrors}}
            <p style="background:#ff4c4c;color:white;text-align: center;">
                {{message}}
            </p>
        {{/verifyErrors}}
        {{^verifyErrors}}
            <p style="background:#ff4c4c;color:white;text-align: center;">Something went wrong! 
            Couldn't subscriber you to the newsletter! </p>
        {{/verifyErrors}}
      </template>
    </div>
    <div submit-success>
      <template type="amp-mustache">
        <p style="background:green;color:white;">Thank you for subscribing to our newsletter!</p>
      </template> 
    </div>


  </form>