How to use dynamic resource allocation,got error

Error from server (Invalid): error when creating “dynamic-res-nvidia.yaml”: ResourceClass.resource.k8s.io “nvidia-gpu” is invalid: driverName: Invalid value: “nvidia.com/gpu”: a lowercase RFC 1123 subdomain must consist of lower case alphanumeric characters, ‘-’ or ‘.’, and must start and end with an alphanumeric character (e.g. ‘example.com’, regex used for validation is ‘a-z0-9?(.a-z0-9?)*’)