You have an Azure subscription that contains 10 virtual machines, a key vault named Vault1, and a network security group (NSG) named NSG1. All the resources are deployed to the East US Azure region. The virtual machines are protected by using NSG1. NSG1 is configured to block all outbound traffic to the internet. You need to ensure that the virtual machines can access Vault1. The solution must use the principle of least privilege and minimize administrative effort. What should you configure as the destination of the outbound security rule for NSG1?