Now, as for recording your actual voicemail, you will be prompted to say and record your full name as this is the default voicemail of the Samsung Galaxy S9. If you would like to customize it instead to be a personalized message, follow these instructions.
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.

Your iPhone can now send spam calls directly to voicemail — here's how to set it up. But, if your iPhone thinks it knows the number — like if you've called someone who isn't in your phone In one instance, for example, I had this turned on and my colleague's calls kept going right to my voicemail.
Tap Voicemail in the bottom right corner. 3. Tap Greeting in the top left corner of your screen. In the top left corner, tap Greeting to edit or change your outgoing voice message. 4. Tap Custom if you want to record a custom greeting. To record a personalized message, tap Custom. This will give you options to record a new one.