Hello admin ogsl,
Thanks for posting your question in the Microsoft Q&A forum.
Double-check that the Carbon Optimization Reader role has been correctly assigned at the subscription level. ensure that the Azure Carbon Optimization application is not disabled at the tenant level. This might require contacting your tenant administrator.
Verify that the subscription is active and in good standing. Some preview services may have additional requirements for subscription eligibility.
Please don't forget to close up the thread here by upvoting and accept it as an answer if it is helpful