Service not enabled within domain when attempting from custom code

I have Auth0 set up on my account and enabled on my server. I put all the details into Postman and can get a new access token with no problems. Now I am trying to duplicate that request in code, Business Central AL code to be specific. I am doing everyone right as far as I can tell, but I keep getting “Service not enabled within domain” in my logs.

One thing I did notice was that Postman is passing in a base64 encoded string of the client id and secret in the header. But I am passing the id and secret in the body. Does this matter? Any other ideas of what might be the issue?

Here is my raw details in the log:

  "date": "2022-11-02T20:01:38.402Z",
  "type": "feccft",
  "description": "Service not enabled within domain: https://xxxx/",
  "connection_id": "",
  "client_id": "xxxx",
  "client_name": "Oauth2 Test",
  "ip": "xxxx",
  "hostname": "",
  "user_id": "",
  "user_name": "",
  "audience": "https://xxxx/",
  "scope": "xxxx",
  "log_id": "90020221102200143516310710304445285074357191379970424866",
  "_id": "90020221102200143516310710304445285074357191379970424866",
  "isMobile": false,
  "user_agent": "Other 0.0.0 / Other 0.0.0",
  "id": "90020221102200143516310710304445285074357191379970424866"