The ForAllValues prefix with an empty condition key matches only if the key is missing from the request context.
In AWS Console -
In Terraform -
References:
https://docs.aws.amazon.com/IAM/latest/UserGuide/service_code_examples_iam.html
https://docs.aws.amazon.com/IAM/latest/UserGuide/reference_policies_condition-keys.html
https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_policy