Read 2 Value with bleak via BLE notify from ESP32

[Nietzsche]

Hello, when I read out 2 characteristics via Bleak and BLE, via the command:

async def notification_handler(sender, data, callback):
     spo2_value = numpy.frombuffer(data, dtype=numpy.uint32)

     print("Red values:")
     print(spo2_value)

     # Update the label text
     callback(spo2_value)

... and

async def notification_handler(sender, data, callback):
     red_value = numpy.frombuffer(data, dtype=numpy.uint32)

     print("Red values:")
     print(red_value)

     # Update the label text
     callback(red_value)

Then only one is displayed to me, since both have the same name: notification_handler. If I rename it to notification_handler2, for example, the function no longer works. What can I do there?

Link to the library bleak: https://github.com/hbldh/bleak
GitHub