When the phone is connected to a device with recording capability, you can set the default recorder.
Setting method:
realme UI 7.0: Settings > Sound & Vibration > More > Recording device for Camera, select External microphone or Internal microphone
realme UI 6.0 & 5.0 & 4.0: Settings > Sound & Vibration > Advanced Settings/More > Default Recorder
realme UI 3.0: Settings > Sound & vibration > Advanced Settings > Default Recorder, Auto select or Add on can be selected.
realme UI 2.0: Settings > Sound & vibration > Other Settings > Default Recorder, Auto select or Add on can be selected.
realme UI 1.0: Settings > Sound & vibration > Default audio recorder, Auto select or Add on can be selected.
realme UI R & Go & S & T & U Edition: No option, but it will use the earphone mic to record video when the phone connects to the earphone
1. Choose Auto select
1.1 Always use the phone's microphone to record sound when no earphone is plugged in.
1.2 When a device with recording capability such as an earphone is plugged in, the phone microphone is used to record sound if you are currently recording video; if not, the earphone is used to record sound.
2. Choose Add on
2.1 Always use the phone microphone to record sound when no earphone is plugged in.
2.2 When a device with radio capability is plugged in, it records sound by default