Get Speed and Cadence Measurements (Garmin Cadence Sensor 2) through Python Script BLE

I'm developing a Python script that retrieves the CSC measurement data from a Garmin Cadence Sensor 2. 

I can connect to the device and 'subscribe' to the CSC Measurement Characteristic, but I don't receive any data from it.

On my phone in order to start getting cadence value on WAHOO app I have to click on a specific button, what leads me to think that I need to send a specific command to the device for it to initiate notification of the CSC measurement. But I can't find any information on how to do that!

Has anyone managed to do that? I'm connecting it to a Raspberry Pi trough BLE it that helps! 

Thank you