NOTE: Call forwarding is different than call delegation. Call forwarding will result in received calls only ringing on the line forwarded to and not ringing on the original line called. Call delegation will ring on both the original line and delegated line.
You can forward your calls to an external phone number by customizing your call handling settings. If you have set your Business Hours during your initial phone setup, call forwarding can be used to forward calls to another number after your business hours.
Review the Zoom phone Customizing Call Handling documentation for additional information.