IAM - basic authentication issue

Hi all,

I am trying to test the IAM locally, but I came to a issue. When I turned on the the Basic Authentication, I get an 503 Service Unavailable.
error.

This is the scenario/setup:

• Because I am new to IRIS I need a test sample in IRIS where I can get data from. So I use this tutorial: https://docs.intersystems.com/irislatest/csp/docbook/DocBook.UI.Page.cls?KEY=AFL_rest#AFL_rest_exercise. It works, I can make direct calls to IRIS via Postman.
• Because the goal is to test IAM, I setup the IAM with: https://openedx.learning.intersystems.com/courses/course-v1:InterSystems.... This works also, I can also make a call via Postman.
• But, when I turn on Basic authentication plugin of IAM, I get the following issue: The authentication part works. I really need to supply an user and password. But when I supply it, it gives an 503 Service Unavailible error. So I don't know what went wrong. Because IAM does route the call at point 2.

Thanks for your help in advance,

Chi Wan