A Key Management Service (KMS) key and the Identity and Access Management (IAM) role that Amazon Forecast can assume to access the key.
The Amazon Resource Name (ARN) of the KMS key.
The ARN of the IAM role that Amazon Forecast can assume to access the AWS KMS key. Passing a role across AWS accounts is not allowed. If you pass a role that isn't in your account, you get an InvalidInputException error.
InvalidInputException