Payment Page 1.5.3 exposes four configurable actions after a successful-payment callback:

  1. Confirmation Email
  2. Redirect
  3. Dynamic Message
  4. HTTP Request

These can be enabled in the Settings under Actions After Submit:

The four Actions After Submit choices in the Payment Page 1.5.3 form editor

For details about each Action, please see these docs:

Confirmation EmailRedirectDynamic MessageHttp Requests