How To Enable CORS on CWP?

Hi ,
I'm trying to activate CORS on my server for the last two days with no luck. I enabled CloudFront caching using a plugin and after that, the icons on my website is missing. So I contacted plugin developer and he said CORS is not enabled on my server. My server using Nginx & Varnish & Apache configuration. So It would be great if you can help me to enable CORS on my web server? Thanks in advance 

https://enable-cors.org/server.html