main_2.go

...
func main() {
	mux := http.NewServeMux()

	conf := &oauth2.Config{
		ClientID:     "RANDOM",
		ClientSecret: "RANDOM",
		Scopes:       []string{"offline_access"},
		Endpoint: oauth2.Endpoint{
			TokenURL: "https://oauth.wiremockapi.cloud/oauth/token",
			AuthURL:  "https://oauth.wiremockapi.cloud/oauth/authorize",
		},
		RedirectURL: "http://localhost:8080/consume",
	}

	// Map a route to handle requests to the root path ("/")
	mux.HandleFunc("GET /login", func(w http.ResponseWriter, r *http.Request) {
		// section to redirect user
		url := conf.AuthCodeURL("state", oauth2.AccessTypeOffline)
		http.Redirect(w, r, url, http.StatusTemporaryRedirect)
	})
  ... 
}