1

why is there no option to record whatsapp or FB messenger etc call recording?

2

Voip calls such as Skype, WhatsApp, Viber, WeChat, Hangouts, IMO, Facebook Messenger etc cannot be recorded,
- no matter what Android phone you are using.
- no matter what Android version you are running.
- no matter what recorder in the market you are using.
This is limited by Android. Only normal calls can be recorded.

3

You can record the call from such applications like messenger,whats app etc because those application doesn't provide recording option.