How to work with headers in cross-domain requests?

Question

JavaScript

Server on .net with webApi
I make a request via XMLHttpRequest
The article states that a cross-domain request in XMLHttpRequest can only accept simple headers, and the rest must be explicitly specified.
It turns out that with a normal request, I get all the headers, but in a cross-domain one, only simple ones.
How to specify permissions for these headers?

Answer 1

Helped Access-Control-Expose-Headers
Ie . registered on the server
And everything worked