The other use case is that the registration starts with Fast track registration (FTR). When the client application owner wants to launch a marketing campaign for their prospect users to register HSID, Fast Track Registration link would be generated under a specific marketing campaign.
For this use case, these two changes are required:
The overall flow of FTR is the same. Please see Invitation API integration for the details. The only difference is that add one JSON attribute “campaignId” (Note: the attribute name is different from ID token claim – no underscore) to the API request payload, under context.properties.