How should I start a process defined with a message start?

Summary

How should I start a process defined with a message start?

Content

Hello,

 

I have a process that starts with a message start event. I will call this through a rest webservice which according to documentation I need to get the url from the management tab. The problem is that I am not sure how the payload should be built, Do I sent the parameters through the url? Should I sent them as XML? json? How should it be built? What header should I use?

 

Thanks.

 

 

Gleiry Agustin