I have converted web chat mashup into irame tag as given below . initially, it gives authentication error in chrome but loads webchat within seconds properly .But in  browser console it gives errors "Cannot read property '_bIsIframeOnly' of undefined".

What is best practice for generating webchat channel in iframe style.

below is the sample code:-

.................................................................................................

Webchat channel  mashup code generated by pega
.................................................................................................

<script src ='https://example.com/prweb/app/Appname/?pyActivity=pzIncludeMashupScripts'></script&gt;
<div   
class="display:block;width: 500px;height:700px;"  
data-pega-gadgetname ="PegaGadget" 
data-pega-action ="createNewWork"
data-pega-action-param-classname ="Work-Channel-Chat"
data-pega-action-param-flowname ="pyStartCase"
data-pega-isdeferloaded ="false"
data-pega-applicationname ="Appname"
data-pega-threadname ="STANDARD"
data-pega-resizetype ="fixed"
data-pega-url ="https://example.com/prweb/PRChat/app/Appname/"
data-pega-action-param-parameters ='{"channelId":"botid1234"}' >

--------------------------------------------------------------------------------------------------------------------------------------
iframe style code (this code loads chat on click of button , but gives error in chrome browser console)
.................................................................................................................................................................
<script src ='https://example.com/prweb/app/Appname/?pyActivity=pzIncludeMashupScripts'></script&gt;

<script> function loadGadget() { 

var myIframe=document.getElementById("PegaGadgetIfr");
myIframe.src=myIframe.src+"&channelId=botid1234";
myIframe.style.display = "block";
pega.web.api.doAction(myIframe, "load"); 
}

 </script> 
 <iframe name="PegaGadgetIfr" id="PegaGadgetIfr"  class= "display: none;width: 500px;height:700px;" data-pega-iframe-gadgetname ='PegaGadget' data-pega-resizetype ='fixed'   src="https://example.com/prweb/PRChat/app/Appname/[email protected]&action=createNewWork&isWebMashup=true&sendP3P=y&className=Work-Channel-Chat&flowName=pyStartCase" border="0" frameborder="0"></iframe>
 <button onclick="loadGadget()"> load mashup</button>