Cross-region snapshots for RDS and EBS using KMS encryption.
terraform init
terraform apply -auto-approve
A snapshot of the volume will be already be created by Terraform and encrypted with the primary region KMS key.
To created a copy of the snapshot to the secondary region, run the copy command selecting the KMS key on the secondary region.
aws ec2 copy-snapshot \
--region sa-east-1 \
--source-region us-east-2 \
--source-snapshot-id snap-00000000000000000 \
--encrypted \
--kms-key-id '000000000000000000000000000000000000'