How to initiate a MessageStartEvent Activity using Flowable APIRest

Hi,

I have an active process instance, but when an event happens, I want it to take another path. The way to change to the other path is by using MessageStartEvent.

This is my Process:


This event happens when I am standing on the “Envío a proveedores” task.

According to Flowable documentation, the way to send a message for a particular process is by sending the message and businessKey.

I set a business key for my active process and send the message like this:

POST /flowable-rest/service/runtime/process-instances HTTP/1.1
Content-Type: application/json
{
   "message":"Desistir",
   "businessKey":"TEST6"
}

Response:

{
    "message": "Internal server error",
    "exception": "couldn't instantiate class Desistir"
}

Also try doing this:

PUT flowable-rest/service/runtime/executions/{{ProcessId}}
Content-Type: application/json
{
  "action":"messageEventReceived",
  "messageName":"Desistir"
}

Response:

{
    "message": "Internal server error",
    "exception": "Execution with id '7057dc22-d265-11ee-83be-0242ac180002' does not have a subscription to a message event with name 'Desistir'"
}

Flowable Version : 6.5.1

Any help or suggestion would be greatly appreciated. Thanks in advance!