CORSに抵触して、クライアントとサーバ間でデータのやり取りがうまくいかない

e.Use(middleware.CORS())

package main

import (
	"io"
	"net/http"
	"os"
	"strconv"
	"sync"
	"time"

	"github.com/labstack/echo"
	"github.com/labstack/echo/middleware"
)



type Book struct {
	Title     string `json:"title" form:"title" query:"title"`
	FirstName string `json:"firstname"  form:"firstname" query:"firstname"`
	LastName  string `json:"lastname"  form:"lastname" query:"lastname"`
}

type (
	Stats struct {
		Uptime       time.Time      `json:"uptime"`
		RequestCount uint64         `json:"requestCount"`
		Statuses     map[string]int `json:"statuses"`
		mutex        sync.RWMutex
	}
)

func NewStats() *Stats {
	return &Stats{
		Uptime:   time.Now(),
		Statuses: map[string]int{},
	}
}

func (s *Stats) Process(next echo.HandlerFunc) echo.HandlerFunc {
	return func(c echo.Context) error {
		if err := next(c); err != nil {
			c.Error(err)
		}
		
		s.mutex.Lock()
		defer s.mutex.Unlock()
		s.RequestCount++
		status := strconv.Itoa(c.Response().Status)
		s.Statuses[status]++
		return nil
	}
}

func (s *Stats) Handle(c echo.Context) error {
	s.mutex.RLock()
	defer s.mutex.RUnlock()
	return c.JSON(http.StatusOK, s)
}

func ServerHeader(next echo.HandlerFunc) echo.HandlerFunc {
	return func(c echo.Context) error {
		c.Response().Header().Set(echo.HeaderServer, "Echo/3.0")
		return next(c)
	}
}

func main() {
	e := echo.New()

	// Debug mode
	e.Debug = true

	//-------------------
	// Custom middleware
	//-------------------
	// Stats
	s := NewStats()
	//Use関数でリクエストが飛んできたときに事前に決められた共通の処理ができる
	//Proccessはリクエスト情報を取得する
	e.Use(s.Process)
	e.GET("/stats", s.Handle) // Endpoint to get stats

	// Server header
	e.Use(ServerHeader)

	//CORS
	e.Use(middleware.CORS())

	// Handler
	e.GET("/", func(c echo.Context) error {
		return c.String(http.StatusOK, "Hello, World!")
	})

	e.GET("/show", show)
	e.POST("/save", save)
	e.POST("/save1", save1)
	e.POST("/books", books)


	// Start server
	e.Logger.Fatal(e.Start(":1323"))

}


// http://localhost:1323/show?team=x-men&member=wolverine
func show(c echo.Context) error {
	// Get team and member from the query string
	team := c.QueryParam("team")
	member := c.QueryParam("member")
	return c.String(http.StatusOK, "team:"+team+", member:"+member)
}

// e.POST("/save", save)
func save(c echo.Context) error {
	// Get name and email
	name := c.FormValue("name")
	email := c.FormValue("email")
	return c.String(http.StatusOK, "name:"+name+", email:"+email)
}



// e.POST("/books", books)

func books(c echo.Context) error {
	name := c.FormValue("title")
	firstName := c.FormValue("firstName")
	lastName := c.FormValue("lastName")
	b := &Book{}
	b.Title = name
	b.FirstName = firstName
	b.LastName = lastName

	if err := c.Bind(b); err != nil {
		return err
	}
	return c.JSON(http.StatusCreated, b)
}

import axios from "axios";
import './App.css';

axios.defaults.withCredentials = true;

function App() {
  const handleSubmit = event => {    
    axios.get('http://localhost:1323/', {
   
    }).then((res)=>{
      console.log(res)
    }).catch((res)=>{
      console.log(res)
    })
  };

  return (
    <button onClick={event => handleSubmit(event)}>ボタン</button>
 
  );
}

export default App;

e := echo.New()
e.Use(middleware.CORSWithConfig(middleware.CORSConfig{
  AllowOrigins: []string{"http://localhost:3000"},
  AllowHeaders: []string{echo.HeaderOrigin, echo.HeaderContentType, echo.HeaderAccept},
}))