Integration: Graylog x DFIR-IRIS

I’m trying to configure graylog alerts to go to Iris, but without success.
Has anyone already done this configuration?
I tried using the HTTP Notification and Custom HTTP Notification option.

I tried to configure it, but it gives the following error:
Expected successful HTTP response [2xx] but got [405].
Expected successful HTTP response [2xx] but got [404].

Document referring to the IRIS API (API - Documentation)

I investigated this earlier (Custom HTTP Notification -> DFIR-IRIS) but got nowhere. Honestly, I’ve had a lot of trouble using Graylog’s Custom HTTP notifications. For instance, I can’t even get it to work with Gotify (which you would think would be fairly straight forward).

C’est la vie