How to get the value of checkbox and change it dynamically

I have Contact Form 7 checkbox in my wordpress website and the values of my forms are sent to a Web Service.

To send the values to the webservice i use a plugin named 3rd Party Integration.

The Web service accept only some technical ids and my checkbox propose non technical ids.

When someone fill my form, can we get the value (which is non technical id) of the checkbox and "transform" it to another one (technical id) before the form send values to the Webservice ?

I notice that the plugin contact form 7 allow additional javascript in the configuration.

Thanks