Switching off engine using Gt06 protocol

I have installed the server and everything works as expected. However,i am wondering how i would actually switch off the engine. Of importance is how i would actually shut the engine from my source code that i have separate from the server and probably not even using the language of the server - jave.

I know this would be possible using sms,but is this something that can be done from my sourcecode by contacting the device ip address and such stuff.

Thanks.

Update:

Any method even if its java to switch off the engine and to start the engine in gt06 protocol is welcome.

Traccar includes API that you can use from your app:

https://www.traccar.org/traccar-api/

Where can i find a list of all methods available?. Is the api made of rest?.

I haven't got time to write proper documentation yet, so the best source of information is the code:

https://github.com/tananaev/traccar/blob/master/src/org/traccar/model/Command.java