lp mobile html plugin create a custom button by identifying the triggerSelector

lp-mobile-custom-button.html

<script type="text/javascript">
  /* LP Mobile JS Configuration */
  var _LP_CFG_ = {
    app_id : "YOUR_MOBILE_SITE_ID",
    options : {
      // All configuration options defined in here
      triggerSelector : '.help-btn' // Replace with a selector to your help button(s)
    }
  };
  /* End of Configuration */
 
  /* LP Mobile JS include */
  (function(){var a=_LP_CFG_.lpjsid="lpjs-"+(new Date).getTime(),b=document.createElement("script"),s=document.getElementsByTagName("script")[0];b.id=a;b.type="text/javascript";b.async=true;b.src="https://d3tpuxked45kzt.cloudfront.net/lp_lib/liveperson-mobile.js";s.parentNode.insertBefore(b,s)})();
  /* End of Include */
</script>