"Forgot password?" on Nextcloud login page

Forgot password? on the Nextcloud login page only works for users which were created via Nextcloud, not for users which were synchronized from UCS via LDAP. Since most of our Nextcloud users are UCS users, it would be good enough for us to change the link to https://ucs.domain.tld/univention/self-service/#passwordreset. How can this be achieved?