How to map Nginx http response header?

Server NGINX
1

I tried several configs but seems to not work, like…

Code:

map $http_x_litespeed_cache_control $nocacheheader {
    default      0;
    no-cache   1;
    }

Code:

map $upstream_http_x_litespeed_cache_control $nocacheheader {
    default      0;
    no-cache   1;
    }

Code:

map $sent_http_x_litespeed_cache_control $nocacheheader {
    default      0;
    no-cache   1;
    }

Page is still cached.
What is the correct format?

My HTTP response header:

x-litespeed-cache-control no-cache
Thanks!