   //read updated parameters
   strcpy(mqtt_server, custom_mqtt_server.getValue());
   strcpy(mqtt_port, custom_mqtt_port.getValue());
-  strcpy(blynk_token, custom_blynk_token.getValue());
+  strcpy(api_token, custom_api_token.getValue());
 
   //save the custom parameters to FS
   if (shouldSaveConfig) {


//define your default values here, if there are different values in config.json, they are overwritten.
char mqtt_server[40];
char mqtt_port[6] = "8080";
char blynk_token[34] = "YOUR_BLYNK_TOKEN";

//flag for saving data
bool shouldSaveConfig = false;

    DynamicJsonBuffer jsonBuffer;
    JsonObject& json = jsonBuffer.createObject();
    json["mqtt_server"] = mqtt_server;
    json["mqtt_port"]   = mqtt_port;
    json["api_token"]   = api_token;

    File configFile = SPIFFS.open("/config.json", "w");
    if (!configFile) {
