icinga2 : missing UnAcknowledge callback action

[aderumier]

Hello,
UnAcknowledge callback action have been added some year ago for icinga1 && nagios

1acf234#diff-f3d784d6a4b20d73c2c661adda2a2866

It's seem that icinga2 is not implemented

I have tried to add
actions.UnAcknowledge.script=icingaActionExecutor.groovy

and I have this error

19/08/27 10:48:11.059 WARN: [UnAcknowledge]: Will execute action for alertId 6fc8b20b-4404-480b-9144-b202e4f6e528-1566893890551
19/08/27 10:48:12.459 WARN: [UnAcknowledge]: Could not execute at Icinga. Icinga Response:{"error":404.0,"status":"The requested path '' could not be found or the request method is not valid for this path."}