Previous versions of Portals (ADX Studio) had the ability to configure IPN for PayPal integration.
Use Case scenario is when the Portal is used for e-commerce purposes (also without a full shopping cart experience, for example a direct purchace of an e-book)
Old ADX Studio documentation about the functionality:
Thank you for reaching out. Your suggestion seems to be a duplicate of the following suggestion:https://experience.dynamics.com/ideas/idea/?ideaid=5e95c894-30b0-e611-80c2-00155d460d59
Senior Program Manager