How to add header with "Access-Control-Allow-Origin: *" in Umbraco 9?

Hi,

I have some JavaScript that needs to have access to external json. How do I configure my site to allow this?


This is a companion discussion topic for the original entry at https://our.umbraco.com/forum/108573-how-to-add-header-with-access-control-allow-origin-star-in-umbraco-9