Open the Phone app
Tap the menu icon or More options
Go to Settings
Tap Voicemail
Select Advanced Settings or Voicemail settings
Tap Greeting or Voicemail greeting
Choose Record a new greeting or Default greeting
Record your message
Save the greeting
Set voicemail number if needed
Adjust voicemail notifications if available
Enable visual voicemail if supported by your carrier
Contact your carrier if voicemail options are missing