After the auto answer function is turned on, the incoming call will be automatically answered when the earphones and the Bluetooth device are connected. You can also set a Delay auto answer after turning on the switch.
Path:
realme UI 7.0 & 6.0 & 5.0 & 4.0 & 3.0: Google Dialer > Three dots in the upper right corner > Settings > Call accounts > Answer / End calls > Auto answer calls when connected to external audio device
realme UI 2.0 & 1.0: Google Dialer > Two dots on the upper right corner > Settings > Calling accounts > Answer/End calls > Auto answer calls when connected to external audio device
realme UI R & Go & T & S & U Edition: Not supported