Terraform and Kubernetes environment

In Terraform secret resource:
data = {
aws_access_key_id = base64decode("…")
aws_secret_access_key = base64decode("…")
mongo_initdb_username = base64decode("…")
mongo_initdb_password = base64decode("…")
}
I getting
Kubernetes secret yaml:

data:
aws_access_key_id:
aws_secret_access_key:
mongo_initdb_password:
mongo_initdb_username:

and it not work in Kubernetes cluster, why, because the Terraform not perform correct, in cluster for key must have string value, insufficiently characters “”

Question:
How in Terraform I need to write characters “” that it perform correct to Kubernetes cluster?
Thanks