1

Is Boldbeast can record the call in stereo mode ?
Each party in a channel ?

Alcatel Pixi 4 android 6 record the call in stereo mode

2

Most Android phones don't support stereo recording, usually they just support two channels with the same audio. A few phones may support stereo. Please root the phone, use Record Mode 5, MP4 or AAC format to test if it works or not.

3

Thank you
I do not know how to root phone
and the safety tools to use
Can you help me please?

4

There are more than 10000 Android phones, the root approach is different from phone to phone, please google "Root AAAA" to know how to root your phone, here AAAA is your phone model, for example "Root Pixel3".