How to overcome Access-Control-Allow-Origin error on server response 400?

Question

Nginx

The server is written in express. In front of it is Nginx. Requests go from the main domain to the api.domain.ru subdomain.
If the server does not respond with 200, then an error occurs:

No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'https://domain.ru' is therefore not allowed access. The response had HTTP status code 401.

And the server cannot respond differently to erroneous requests))) How to be?

Answer 1

Answer found here: serverfault.com/a/700670