在golang服务器中面临CORS问题

I have written this code in my Go server:

func main() {
    r := chi.NewRouter()
    cors := cors.New(cors.Options{
        AllowedOrigins:     []string{"*"},
        AllowOriginFunc:    func(r *http.Request, origin string) bool { return true },
        AllowedMethods:     []string{"GET", "POST", "PUT", "DELETE", "OPTIONS"},
        AllowedHeaders:     []string{"Accept", "Authorization", "Content-Type", "X-CSRF-Token"},
        ExposedHeaders:     []string{"Link"},
        AllowCredentials:   true,
        OptionsPassthrough: true,
        MaxAge:             3599, // Maximum value not ignored by any of major browsers
    })
    flag.Parse()

    // A good base middleware stack
    r.Use(cors.Handler)
    r.Use(middleware.RequestID)
    r.Use(middleware.Logger)
    r.Use(middleware.Recoverer)
    r.Use(middleware.URLFormat)
    r.Use(render.SetContentType(render.ContentTypeJSON))
    r.Use(middleware.Timeout(60 * time.Second))

    r.Group(func(r chi.Router) {

        r.Route("/api", func(r chi.Router) {
            r.Route("/items", func(r chi.Router) {
                r.Get("/", allItems)
                r.Route("/{barcode}", func(r chi.Router) {
                    r.Get("/", getItem)
                    r.Put("/", updateItem)
                })
                r.Post("/", postItem)
                r.Delete("/", deleteItem)
            })

            r.Route("/sale_lines", func(r chi.Router) {
                //  r.Use(cors.Handler)
                r.Post("/", postSales)
                r.Put("/", updateSales)
                r.Delete("/", deleteSales)

            })
        })
    })
    http.ListenAndServe(":8080", r)
}

I am facing the problem that when I am calling the api from my react app, it is giving me an error like this:

What problem is there which I am missing?