aws ec2 modify-ebs-default-kms-key-id
Changes the default KMS key for EBS encryption by default for your account in this Region. AWS CLI reference
2 options Its page in the AWS CLI reference
Options
--dry-runChecks whether you have the required permissions for the action, without actually making the request, and provides an error response.--kms-key-idThe identifier of the KMS key to use for Amazon EBS encryption.