Access to XMLHttpRequest

I’m trying Data Client to claim data on server side. In the console I get this message:

Access to XMLHttpRequest at ‘’ from origin ‘’ has been blocked by CORS policy: No ‘Access-Control-Allow-Origin’ header is present on the requested resource.

What I need to do to get Data Client claim request? And does this error have anything with Shopify?


Try to publish Data Client, it should fix the issue.

Hi Ira,
Thanks for the reply. I did try that already.

By saying ‘publish Data Client,’ you mean to publish sever side container, right?

yes, correct. publish server container

Yes, that was done and still getting this message.

Can you please share the URL of the site on which you getting this error?

Also, we created a video on how to configure Data Tag/Data Client Sending data from the GTM web container to the server container using Data Tag/Data Client - YouTube

Maybe it helps you to find a solution.

Hi @Denis,
Thanks for the link I already checked that out and didn’t find any missteps. I didn’t change anything but there is no more of this error message in console. Still, Data Client is not collecting the requests.

Here is my GTM set up video link: Facebook API.webm - Google Drive

Link to the site is:

If you need anything else, let me know.


I checked your video and site.

I mentioned that you use Shopify. For Shopify we have a dedicated tutorial on how to setup Facebook Conversion API and ready to import configured GTM containers.

If you want to fix the current setup. I can suggest you change the request type in the Data tag from POST to GET.