The password reset service is disabled via configuration registry

Hello my friends. At https://server_address/univention/self-service/#page=passwordreset it shows this message:

Internal server error: The service is temporarily not available.
Server error message:
The password reset service is disabled via configuration registry

How can i enable it?

UCS Version: 4.4-4 errata579 (Blumenthal)
UMC Version 11.0.4-63A~4.4.0.202004211448

Hello guys… can someone help me?