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Todd DeRosa 4Todd DeRosa 4 

Problem using CometD in experience cloud

Hi everyone, I am trying to receive a platform event for an aura component to work in both lightning and experience cloud.  I tried the empapi, but that only works in lightning.  I then tried cometd and got it to work in lightning, but when testing in experience cloud am struggling with the following error on the cometd.configure call:  

Access to XMLHttpRequest at '' from origin '' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

I have added both urls shown above to the CORS policy page and can't find how to add the access-control-allow-origin header to the request. Here is the code where the error is occuring. I am hard coding the url for now until I can get this to work:

       action.setCallback(this, function(response) {
            var sessionId = response.getReturnValue();
            var cometd = new;
                url:  '' + '/cometd/52.0',
                    requestHeaders: { Authorization: 'OAuth ' + sessionId},
                appendMessageTypeToURL : false
            cometd.websocketEnabled = false;
I used LWC.
Sample Code: