The access node must have access to the global and regional STS endpoints.
Global STS endpoints: The global STS endpoint is https://sts.amazonaws.com.
Regional STS endpoints: For example, for instances in a region called us-east-1, the endpoint is https://sts.us-east-1.amazonaws.com.
For more information about AWS service endpoints, see AWS service endpoints on the AWS documentation site.
For more information about STS endpoints and quotas, see AWS Security Token Service endpoints and quotas on the AWS documentation site.