Facing CORS error for Sunny Landing page integration

Hello team,

I am trying to integrate sunny landing page with Creatio Atlas and am facing below error.

Access to XMLHttpRequest at 'https://019205-marketing.creatio.com/0/ServiceModel/GeneratedObjectWebFormService.svc/SaveWebFormObjectData' from origin 'http://mydemodomain.demopage.co' 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.

How do I overcome this? I notice sometimes using OpenID when I login to creatio, I get this error as well? Is there a work around for this?

Thanks