This FAQ will show you how to override the external transfer number on Dynamic IVR.
This is mainly used if you have the same Dynamic IVR but use a different transfer number instead of cloning the Dynamic IVR.
From the sample below:
Name of the Dynamic IVR: Sample Dynamic IVR
The Destination, Route To settings is configured to External Numbers (8881234567)
From the Campaign General settings. You can use the same Dynamic IVR (Sample Dynamic IVR) and then you can enter the transfer number that you would like to override from your Dynamic IVR settings.
From this settings, Since the override transfer number is configured. The system will then use the transfer number 8884565454 instead of the external number 8881234567 from your Dynamic IVR.