Access IntraWeb application from nginx reverse proxy

[ccy]

Usually, configure nginx reverse proxy is easy and straight forward, but I couldn't get it work with IntraWeb application.

For example, I wish to access IntraWeb applicaton from URL http://www.example.com/intraweb

The Intraweb application is accessible from http://10.1.1.1:8888/

Here is my nginx configuration:

    location /intraweb {
        proxy_pass       http://10.1.1.1:8888$request_uri;
        proxy_set_header Host 10.1.1.1:8888;
    }

But it doesn't work.  Is there any setting I need to configure in IntraWeb?