mailcow-dockerized/data/conf/nginx/includes/sogo_proxy_auth.conf

auth_request /sogo-auth-verify;
auth_request_set $user $upstream_http_x_user;
auth_request_set $auth $upstream_http_x_auth;
auth_request_set $auth_type $upstream_http_x_auth_type;
proxy_set_header x-webobjects-remote-user "$user";
proxy_set_header Authorization "$auth";
proxy_set_header x-webobjects-auth-type "$auth_type";