Dgraph K8s Installation with Helm : invalid metadata.name

Trying to install dgraph k8s cluster with helm, I get these errors:

root@k8s-eu-1-control-plane-node-1:~#    helm install v23.1.0 dgraph/dgraph --set image.tag="v23.1.0"
Error: INSTALLATION FAILED: 6 errors occurred:
    * Service "v23.1.0-dgraph-zero-headless" is invalid: metadata.name: Invalid value: "v23.1.0-dgraph-zero-headless": a DNS-1035 label must consist of lower case alphanumeric characters or '-', start with an alphabetic character, and end with an alphanumeric character (e.g. 'my-name',  or 'abc-123', regex used for validation is '[a-z]([-a-z0-9]*[a-z0-9])?')
    * Service "v23.1.0-dgraph-alpha-headless" is invalid: metadata.name: Invalid value: "v23.1.0-dgraph-alpha-headless": a DNS-1035 label must consist of lower case alphanumeric characters or '-', start with an alphabetic character, and end with an alphanumeric character (e.g. 'my-name',  or 'abc-123', regex used for validation is '[a-z]([-a-z0-9]*[a-z0-9])?')
    * Service "v23.1.0-dgraph-alpha" is invalid: metadata.name: Invalid value: "v23.1.0-dgraph-alpha": a DNS-1035 label must consist of lower case alphanumeric characters or '-', start with an alphabetic character, and end with an alphanumeric character (e.g. 'my-name',  or 'abc-123', regex used for validation is '[a-z]([-a-z0-9]*[a-z0-9])?')
    * Service "v23.1.0-dgraph-zero" is invalid: metadata.name: Invalid value: "v23.1.0-dgraph-zero": a DNS-1035 label must consist of lower case alphanumeric characters or '-', start with an alphabetic character, and end with an alphanumeric character (e.g. 'my-name',  or 'abc-123', regex used for validation is '[a-z]([-a-z0-9]*[a-z0-9])?')
    * StatefulSet.apps "v23.1.0-dgraph-zero" is invalid: metadata.name: Invalid value: "v23.1.0-dgraph-zero": must not contain dots
    * StatefulSet.apps "v23.1.0-dgraph-alpha" is invalid: metadata.name: Invalid value: "v23.1.0-dgraph-alpha": must not contain dots