Is it possible to call External REST API from Redwood External Supplier Registration Page (VBS)?

Hi,

We have a requirement to validate a number entered in a DFF field during Redwood External Supplier Registration. This validation must be performed by calling an external REST API. If the API response includes the entered number, the user should be allowed to proceed. Otherwise, the system should prevent the supplier registration.

Can this validation be implemented either directly on the DFF field or triggered on clicking the Save button using VBS?