I am using a generic webhook plug-in that has recently been released for Jenkins.  I have defined a job to Jenkins and I can see the webhook getting to Jenkins but the payload is not being placed in the target location.
When trying to use this configuration I am getting a 403 FORBIDDEN when trying to invoke jobs in Jenkins. I have used the API key of the user that the web service task runs under.

CA Endevor Software Change Manager
Jenkins

The Jenkins wiki has actually provided a way for me to authenticate via a token along with the API token that the webhook supports.