You can subscribe to be notified of ESP events using this

In your initialise

	ESP_ERROR_CHECK( esp_event_loop_init(event_handler, NULL) );

Event handler fucntion

//***************************************
//***************************************
//********** ESP EVENT HANDLER **********
//***************************************
//***************************************
//Call this at startup:
//ESP_ERROR_CHECK( esp_event_loop_init(event_handler, NULL) );
static esp_err_t event_handler(void *ctx, system_event_t *event)
{
    switch(event->event_id)
    {
    case SYSTEM_EVENT_STA_START:
        //WiFi connected

        break;

    case SYSTEM_EVENT_STA_GOT_IP:
        //WiFi got IP

        break;

    case SYSTEM_EVENT_STA_DISCONNECTED:
        //WiFi lost connection
        
        break;

    default:
        break;
    }
    return ESP_OK;
}
/* AVAILABLE EVENTS:
    SYSTEM_EVENT_WIFI_READY = 0,           //< ESP32 WiFi ready
    SYSTEM_EVENT_SCAN_DONE,                //< ESP32 finish scanning AP
    SYSTEM_EVENT_STA_START,                //< ESP32 station start
    SYSTEM_EVENT_STA_STOP,                 //< ESP32 station stop
    SYSTEM_EVENT_STA_CONNECTED,            //< ESP32 station connected to AP
    SYSTEM_EVENT_STA_DISCONNECTED,         //< ESP32 station disconnected from AP
    SYSTEM_EVENT_STA_AUTHMODE_CHANGE,      //< the auth mode of AP connected by ESP32 station changed
    SYSTEM_EVENT_STA_GOT_IP,               //< ESP32 station got IP from connected AP
    SYSTEM_EVENT_STA_LOST_IP,              //< ESP32 station lost IP and the IP is reset to 0
    SYSTEM_EVENT_STA_WPS_ER_SUCCESS,       //< ESP32 station wps succeeds in enrollee mode
    SYSTEM_EVENT_STA_WPS_ER_FAILED,        //< ESP32 station wps fails in enrollee mode
    SYSTEM_EVENT_STA_WPS_ER_TIMEOUT,       //< ESP32 station wps timeout in enrollee mode
    SYSTEM_EVENT_STA_WPS_ER_PIN,           //< ESP32 station wps pin code in enrollee mode
    SYSTEM_EVENT_AP_START,                 //< ESP32 soft-AP start
    SYSTEM_EVENT_AP_STOP,                  //< ESP32 soft-AP stop
    SYSTEM_EVENT_AP_STACONNECTED,          //< a station connected to ESP32 soft-AP
    SYSTEM_EVENT_AP_STADISCONNECTED,       //< a station disconnected from ESP32 soft-AP
    SYSTEM_EVENT_AP_STAIPASSIGNED,         //< ESP32 soft-AP assign an IP to a connected station
    SYSTEM_EVENT_AP_PROBEREQRECVED,        //< Receive probe request packet in soft-AP interface
    SYSTEM_EVENT_GOT_IP6,                  //< ESP32 station or ap or ethernet interface v6IP addr is preferred
    SYSTEM_EVENT_ETH_START,                //< ESP32 ethernet start
    SYSTEM_EVENT_ETH_STOP,                 //< ESP32 ethernet stop
    SYSTEM_EVENT_ETH_CONNECTED,            //< ESP32 ethernet phy link up
    SYSTEM_EVENT_ETH_DISCONNECTED,         //< ESP32 ethernet phy link down
    SYSTEM_EVENT_ETH_GOT_IP,               //< ESP32 ethernet got IP from connected AP
*/