How to default the External BP Number in Supplier UI

Hi Experts,

I am having an requirement to make the  next available BP Number as defaulted on the UI for the  BP Group having the external number range.

I have done all the configurations as per the standard documentation for making it as external number range for that BP group, but currently the requester is entering manually the next available number in the UI , but how can we make the next available number as defaulted for that BP Group.

Any inputs will be appreciated.

Regards

Prateek