How to set cookies in Go?

Question

go

I'm trying to set Cookie in Golang, but for some reason it doesn't set ((
Tell me what I'm doing wrong.

func HandleUser(next http.Handler) http.Handler {
  return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
    if cookie, err := r.Cookie("ssid"); err == nil {
      logger("cookie is ", cookie)
    } else {
      logger(err.Error())
      expiration := time.Now().Add(365 * 24 * time.Hour)
      cookie := &http.Cookie{
        Name:     "ssid",
        Value:    "shop",
        Path:     "/",
        Expires:  expiration,
        HttpOnly: true,
        SameSite: 4,
        Secure:   true}
      http.SetCookie(w, cookie)
    }
    if cookie, err := r.Cookie("ssid"); err == nil {
      fmt.Println("cookie is ", cookie)
    }
    next.ServeHTTP(w, r)
  })
}