ELM327 and ECU Connection Problem

Hello, I brought the Bluetooth Mini device named Super Mini ELM327 to see and delete the error codes on my 2003 model 206 1.4 HDI.

I can connect to the ELM327 device via bluetooth via the phone, but I cannot find the correct protocol when connecting to the ECU.

First of all, is my vehicle OBD2 compatible?

If compatible, do you know the vehicle's communication protocol?

You cannot use the device you bought in diesel vehicles before 2004.