Post-registration redirect for Okta Sign-In Widget with Identity Engine

How do we customize post-registration redirects using Identity Engine with the Okta Sign-In Widget? In the Okta Classic engine, we could supply fromURI and the sign-in widget would redirect to our app after the user finished registering. However, that feature now appears not to work; instead, the user is dropped into the Okta Dashboard. (Login redirects still work as before.)

What is the best way to force a redirect to a specific page after registration is complete?