So root is a must on many devices to record phone calls from the phone line where manufacturers didn’t implement the required functionality. But it doesn’t mean the root is a savior for any device as call recording can be broken on the hardware level. Root helps often, but not always.
The app has different recording methods. If you’re lucky enough, the app won't fail to record both sides over Standard API recording method without root.
If you have tried every audio source for Standard API and the app didn’t record or recorded just your voice, it means that the manufacturer has either failed to implement, or blocked call recording on the system level.
You need to have root permissions to try other recording methods.
Record phone calls
• In call control
• Call confirm
• After call actions dialog
• Edit info about recordings
• Volume control
and also emailing record to friends via bluetooth