It is a service method created in the service.cs file and it is not created in the component. I understood if we created in the component then we can invoke method(like custom method).
From your reply: Only methods defined in the meta will be listed as data source methods....can I know how to do this please?
steps to do:
data ->select datasource -> infer schema -> expand tables in entities -> enable table which we want to generate the invoke data source method