// typedef enum {
//     WIFI_COUNTRY_POLICY_AUTO,   /**< Country policy is auto, use the country info of AP to which the station is connected */
//     WIFI_COUNTRY_POLICY_MANUAL, /**< Country policy is manual, always use the configured country info */
// } WIFI_COUNTRY_POLICY;

// typedef struct {
//     char cc[3];               /**< country code string */
//     uint8_t schan;            /**< start channel */
//     uint8_t nchan;            /**< total channel number */
//     uint8_t policy;           /**< country policy */
// } wifi_country_t;

WiFi.mode(WIFI_STA);
const wifi_country_t COUNTRY_US{"US",1,11,WIFI_COUNTRY_POLICY_AUTO};
const wifi_country_t COUNTRY_CN{"CN",1,13,WIFI_COUNTRY_POLICY_AUTO};
const wifi_country_t COUNTRY_JP{"JP",1,14,WIFI_COUNTRY_POLICY_AUTO};
esp_wifi_set_country(&COUNTRY_US);