If you use your phone when you are driving, you must use a h..... f. phone. voice mail. If you call someone and their mobile isn't on, you can leave a message on their v. m.
With this method, you don’t need a third-party app. Call the person you want to chat with, then tap the “Add Call” button on your phone’s screen. Dial your own phone number—the one you’re calling from. This will take you to your voicemail. Once your voicemail has started recording, tap the “Merge Calls” button on your screen. Now, you’ll record your phone conversation onto a voicemail message. When you’re done with the call, you can tap the share button to export it to your Mac via Airdrop, to the Voice Memos app, or transfer it via email or text message. The file is recorded as an M4A, so depending on what you want to do with it, you may need to convert it to MP3 before uploading it to other apps.

Website: https://blog.youmail.com/2020/05/what-is-visual-voicemail-and-why-should-you-care/
While this app has the exact same name as the iOS app we listed above, it’s made by a completely different developer. This version includes customizable skins and the ability to record calls or notes as MP3s. Instead of having to tap a button, you can also simply shake your phone to instantly start recording a call. You can also choose to sync your stored calls with Dropbox and select particular contacts whose calls you always want to record (and store).