CORS error after adding cloudflare

[cagadasajm]

I have an API and web application on separate sub-domains (https://api.example.com and https://portal.example.com). I am getting CORs error after using Cloudflare.
I researched the whole day yesterday and can’t find a fix to the issue.

[sdayman]

It might be this:

CORS policy problem

For whoever finds this later, the issue is that Access-Control-Allow-Origin: * does not work in conjunction with XMLHttpRequest withCredentials. You need to set the value of Access-Control-Allow-Origin in the response to be the same value as the Origin request header. Check the specification for details.