Error Message "Event Key Not Defined"

Requests I send to only responds back with

    "message": "Event Key Not Defined"

even though my request schema looks like this:

    "eventKey": "arbitrary string",
    "hookUrl": "<insert working URL here>"

Why am I getting this error?

Good morning Chris!

Is the eventKey that you are passing as part of the request a valid entry from the list provided on this endpoint?

Thank you for your response! I didn’t have the correct event type like you suggested. After I added a proper event key, I got the expected response back.