https://demo.orthanc-server.com/

It it possible have configuration file of demo?

And it possible to send query to this server? How is the port and ip?

The demo server uses plain Docker, and is made read-only with the following Lua script:
https://book.orthanc-server.com/users/docker.html
https://book.orthanc-server.com/users/lua.html#filtering-incoming-rest-requests

The REST API is available as follows:

$ curl https://demo.orthanc-server.com/system

Reference: https://book.orthanc-server.com/users/rest.html