Cloud retail activation - D365

[Noobish]

Im getting an error when activating the Activate Retail Cloud POS.

DA1018 - The authorization token issuer is invalid. An identity provider with a matching issuer was not found in the system.

Followed this link but still getting same error.

https://dynamicsuser.net/ax/b/msdynaxsupport/posts/error-the-authorization-token-issuer-is-invalid-an-identity-provider-with-a-matching-issuer-was-not-found-in-the-system-upon-mpos-activation

Any help, thanks!