Tap on the Google Fi app on your device’s home screen. Tap on the Account tab. Under Phone settings, tap on Voicemail. Tap on Manage greeting. Tap on the Microphone button to record a new voicemail message, or skip ahead to step 8. Tap on Keep to save the new message, or on Redo to try another one.
Enter a name for the new greeting and then tap Save. Change your greeting. To use a different greeting that you've already recorded or switch back to the default greeting: On your Android device, open the Google Voice app . At the top left, tap Menu Settings. In the Voicemail section, tap Voicemail greeting.

When you first set up your Android phone, it may ask you to record your greeting for the caller. You can also keep the default greeting stored on the device. But, in future, if you want to customize the Voicemail greeting or want to create a new one, then you may need to delete the old recordings from Android. It may not be necessary depending on the Android device model & version; it’s good to know the process.
Tap a message notification. When you get a voicemail, you can check your message from the notification on your phone. Swipe down from the top of the screen. Tap Voicemail . Call your voicemail. You can call your voicemail service to check your messages. Open the Phone app . At the bottom, tap Dialpad .