az relay --help Manage Azure Relay Service namespaces, WCF relays, hybrid connections, and rules.

[addaxnasom]

Group
    az relay : Manage Azure Relay Service namespaces, WCF relays, hybrid connections, and rules.

Subgroups:
    hyco      : Manage Azure Relay Service Hybrid Connection and Authorization Rule.
    namespace : Manage Azure Relay Service Namespace.
    wcfrelay  : Manage Azure Relay Service WCF Relay and Authorization Rule.