You can create a VPC endpoint by following the instructions at Creating an Endpoint.
If you use a security group to restrict traffic to your VPC, make sure that your security group allows traffic to or from your endpoint according to your use case.
Note: Currently, the only available endpoints are Amazon S3 buckets in the same region as your VPC. For other considerations you should keep in mind when planning your VPC endpoint, see Endpoint Limitations.
If you continue to experience difficulties, please open a case with the TD SYNNEX Public Sector Operations Center.