How to configurate WebChat WebSocket for NginX?

The first configuration must be defined as an http parameter, and second one must be defined as a server parameter. For proxy_pass parameter, web link must be defined.
1    map $http_upgrade $connection_upgrade {
        default upgrade;
        ''      close;
    }
2    location /chathub {
            proxy_pass http://webchat.abc123.com;
            proxy_pass_header  Set-Cookie;
            proxy_http_version 1.1;
            proxy_set_header Upgrade $http_upgrade;
            proxy_set_header Connection $connection_upgrade;