Test Prowl

I new to HA but not new to home automation in general. I’m running a Fibaro HC2 and a Domoticz installation. the plan is to migrate from Domoticz to HA for various reasons.
I have configured

  - name: notify
    platform: prowl
    api_key: 6b6f9.....

in my configuration.yaml.
In the automation.yaml I added this:

- alias: "Test"
# Notify me on my mobile phone of an event
    - platform: state
      entity_id: binary_sensor.kantoor_motion_sensor_34
      to: on
    - service: notify.Prowl
        message: "beweging in kantoor"

however no prowl messages are received.
How can I test the basic Prowl functionality to check where the problem is?

try with all lower case in the service. All service names (along with entity_ids, device_ids, etc) are always lower case.

    - service: notify.prowl
        message: "beweging in kantoor"