Go to https://zoom.us/signin.
Sign in with your CUA Google account. (Be sure to use the "with Google option)
Next to Voicemail Greeting, click the “Audio” icon or “Manage”.
Choose Add Audio or Upload.
You can either:
Record directly: Use your computer microphone to record a new greeting.
Upload a file: Upload an existing MP3 or WAV file (up to 10MB).
Once recorded or uploaded, click Save.
Your new voicemail greeting will now play whenever callers reach your voicemail.