2 leg auth, Create customer Failing kind of

Hey Guys,
I hope someone in this thread may be able to help shed some light on what is happening. I have a mobile app with simple auth and can login a client with no issues, but as soon as try to login a CUSTOMER, I am running into errors constantly.

There are some noticeable differences between a client and a customer in the token creation process from the a standpoint of the http body, and this where I am afraid I running into issues. I have tried multiple different body configs using all the examples in the current docs, and some from the forums too, but if I can’t get past the errors listed below, with any customer account i try to create.

As I said, I can generate the access token and login with no problems for a CLIENT, BUT when I attempt the same for a CUSTOMER, I running into error. The customer may or may not actually get created at this point, but as I don’t receive token in return and only errors, my suspicion is that they don’t.

What I am asking for, is for a current, meaning as of July 4th 2020, or a confirmed example from within the last month at the oldest, of a request, that will generate a user account and token and return the token. The particle docs on this, I can tell, are either not up to date, or leave out some rather important information.

WORKS FINE for a CLIENT - https://docs.particle.io/reference/device-cloud/api/#generate-an-access-token

Customer First way:
https://docs.particle.io/reference/device-cloud/api/#create-a-customer---client-credentials

Error: [“error”: inval:id_scope, “error_description”: Permission denied]

URL: “(mainURL)/v1/products/(. productID. )/customers”

Customer Second Way:
https://docs.particle.io/reference/device-cloud/api/#generate-a-customer-scoped-access-token

Error: [“error”: invalid_client, “error_description”: The grant type is unauthorised for this client_id]

URL: mainURL + “/oauth/token”

The goal here being, to be able to create a new customer from inside the mobile app. Any help you can provide here would be very much appreciated. Thank you!!!