'instance metadata service'="If the credentials are **not** set via the environment, then it will attempt to get a bearer token via the [instance metadata service](https://docs.microsoft.com/en-us/azure/virtual-machines/windows/instance-metadata-service)."
[Configuration.Additional]
AZURE_POLLING_INTERVAL="Time between DNS propagation check"
AZURE_PROPAGATION_TIMEOUT="Maximum waiting time for DNS propagation"
AZURE_TTL="The TTL of the TXT record used for the DNS challenge"
AZURE_METADATA_ENDPOINT="Metadata Service endpoint URL"