How to collect information during Supplier Registration using an API and share with third party

Summary:

We have a client requirement where a supplier will complete a questionnaire on a third party system and will then receive an email with the supplier registration link

The client wants the supplier to be linked to the third party system whilst the supplier is undergoing the supplier registration process, is this possible to do using REST API and could I attach an identifier to the supplier registration link which would then be a part of the registration request to easily connect the suppliers on the third party system

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