Give me some use case example about how to useFetchClient

can who give me some use case about how to use get, post, put, del in useFetchClient please. thanks.
i need use useFetchClient in admin strapi. I created route, controller and service to get, post, del, put in folder api. But not working. I think problem at sysntax. i don’t clarily about that. Let help me please.