Hi @Ahmed_Abd_El-Hafez,
If you have no prior experience with FreeMASTER tool you can start with our Four Part Webinar Series (the 4th part is focused primarily on FreeMASTER Lite and JSON-RPC API).
Another good resource is the How-To page.
The following pictures shows (on a very high level) what has to be done:

FreeMASTER Lite has a built-in web server that can host the web application that you develop in step 2 (in the above image). When you start FM Lite executable, specify the path to your web app like this:
node.exe --web_root "C:\My_FreeMASTER_Lite_App"
Once it is running, you can open your local web browser and navigate to `localhost:8090` or `127.0.0.1:8090` and check your application. (8090 is the default port number, it can be changed using `--port` argument)
There are no additional steps required to access it from a remote PC. You just need to get the public IP address of the machine FreeMASTER Lite is running on, and open it on the remote PC.
For example:
On the local PC: access https://whatismyipaddress.com/. Let's assume it shows `130.120.110.100`
On the remote PC: open the web browser and navigate to `130.120.110.100:8090`
Should you require more details on any step/aspect, we would be happy to assist you.