Registering /rest is not needed, that's the default base path. I use this module a lot and I always use microflow RestServices.CreateMicroflowServiceWithPath to register a service:
'Module.Microflow' so a string with the full name of the microflow'*' or any role(s) you need'Any description''/v1/my/service' so start with a slash but do not end with a slashRestServices.HttpMethod.GET or the request type that is neededBefore registering the service call Java action RestServices.StartPublishesServicesJava.