Enter a voicemail password then click done. Re-enter password then tap done again. Now go to your voicemail greeting and you will be able to edit your greeting. Close all open apps by double-tapping the home button, then swiping up and off the screen with the app window (not the smaller icon).
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.

Sending a Message. – Lift Handset. – Press Express Msg key or Feature 980. – Enter the mailbox number to send the message to. – To leave your message, press OK or 2. – Record your message at the tone. – To end recording, press OK or #. – To send your message, press SEND or #. Checking Voicemail from an Outside Line.
If you’ve already created a custom voicemail on your iPhone, you can tap Play to see how your voicemail sounds. If you’re interested in creating a new message, tap the Custom button. From here, you can start recording your message by tapping Record and tapping Stop whenever you’re finished. Once you’re finished recording, tap on Play to make sure the message comes across as you’d like and hit Save (in the upper right) to save it as your voicemail.