By following these troubleshooting steps, you should be able to resolve any issues you are experiencing with Voice Memos not working.

Source: https://www.devicemag.com/voice-memos-not-working/

I have used a lavalier microphone with my iPhone and recorded voic-overs for various videos using Voice Memos, and I find it’s as good for that as it is for recording a video call or in-person conversation.

Source: https://www.digitaltrends.com/mobile/i-record-interviews-and-these-are-the-best-free-voice-recorder-apps/