Send Notification from ESP32 to Smartphone using BLE services

Hello, I am using proximiy sensor on 3 entrances of auditorium all the sensors are connected with ESP32. with the help of 12v DC, I am thinking to use ESP32in light sleep mode but the major issue is that I am not able to send the message to my smartphone whenever my individual sensor triggered. If anyone worked with this kind of problem before please give your suggestions

Hi Robson,
I'm not sure how much help I can be since I haven't used the ESP32 yet but there are some general things that you can try.
First, I assume you have the app for your phone and that the ESP32 is recognized and connected to the phone.
Then, check that you get the message if the ESP32 is not in sleep mode and you have the phone near the ESP32. Then try it with the ESP32 in light sleep mode.

The next step is to move the phone further away to see how far you can go without breaking the connection to the ESP32. I know that Bluetooth is only for a limited distance and there may be something in the building that would interfere. If you need a longer distance, you may have to use WiFi connection to the internet.

Hi Robson,
For the purpose that you are asking for BLE is not a good option. Serial Bluetooth will be the good way to go.There are two modes of Bluetooth on the ESP32 one is the classic Bluetooth which can be used to send Serial data and the other is BLE which is used for communicating with other BLE devices. Although your phone could act as a BLE device, for sending sensor information it is better to use the serial Bluetooth option.If you are keen on using BLE then you should use the GATT services to find a service where it allows to send notifications. In my perspective for your application Serial Bluetooth is the way to go.If you wan to know more on what I am talking about or to know how to use ESP32 in Serial Bluetooth mode follow the Serial Bluetooth ESP32 tutorial that is linked. 
Hope this helps