In your application, at the step where you want to prompt the user for
                    credentials, trigger the local flow action 
pyReAuthGadget.
                    This flow action displays the section 
pxReAuthGadget, where
                    the user authenticates. For example, a shopping application can have a button
                    that invokes 
pyReAuthGadget when a user checks out. At run
                    time, 
pxReAuthGadget displays the names of the enabled
                    authentication services so that the user can select a service and provide their
                    credentials. You can optionally modify the user interface by customizing the
                        gadget.
The target of the pyReAuthGadget flow action
                        can be Modal Dialog or Overlay. The Replace Current target, though shown, is
                        not supported.
After the user has authenticated, the gadget invokes
                        the activity pyMigrateDataForReAuthenticated. Pega Platform passes the old guest operator ID and the newly
                        authenticated operator ID as input parameters to this activity. You can
                        extend this activity and use it to copy data, such as the shopping cart
                        contents, from the original user to the newly authenticated user.
For
                        example, a shopping application stores shopping cart information for all
                        active users in the cart table, keyed by operator ID. When the user
                        authenticates, your customized version of
                            pyMigrateDataForReAuthenticated copies the relevant
                        cart data from the old user to the new user and saves the cart.
You
                        can use the when rule pzIsAnonymousUser at any time to
                        check whether the user has reauthenticated. A return value of
                            false indicates that the user has provided valid
                        credentials and has been authenticated. Use this when rule to conditionally
                        display a button or link to pyReAuthGadget.