[Plugin: AddToAny: Subscribe Button] Cant get "a2a_button_google_plusone" to show a button

I had the following on my posts, which works fine. But I want to add a samll Google +1 button in the mixt, the same types as the others I’m showing there.

<!-- AddToAny BEGIN -->
<div class="a2a_kit a2a_default_style">
<a class="a2a_dd" href="https://www.addtoany.com/share_save"></a>
<span class="a2a_divider"></span>
<a class="a2a_button_twitter"></a>
<a class="a2a_button_stumbleupon"></a>
<a class="a2a_button_email"></a>
</div>
<script type="text/javascript" src="https://static.addtoany.com/menu/page.js"></script>
<!-- AddToAny END -->

I tried adding the following (and other variations) to the list but it will not show the +1 icon with the rest. How do I do this?

<a class="a2a_button_google_plusone"></a>

https://www.ads-software.com/extend/plugins/add-to-any-subscribe/