Native call recording is coming to the Poco F2 Pro. The feature has arrived for the Mi A2 Lite and Mi A3 too, although it may not be ready for prime time quite yet. The feature is embedded within the stock Phone app.
https://www.notebookcheck.net/Xiaomi-Mi-A2-Lite-Mi-A3-and-Poco-F2-Pro-are-all-set-to-gain-native-call-recording.480650.0.html
Whenever you touch the call record button, you can hear a loud voice saying "your call is being recording now" and person on other side also hear this.