Man pages matching name authen::u2f::tester in section 3pm:

Authen::U2F::Tester.3pm.en	debian 10 / libauthen-u2f-tester-perl
Authen::U2F::Tester.3pm.en	debian 11 / libauthen-u2f-tester-perl
Authen::U2F::Tester.3pm.en	debian 12 / libauthen-u2f-tester-perl