Man pages matching name plack::test::externalserver in section 3pm:

Plack::Test::ExternalServer.3pm.en	debian 10 / libplack-test-externalserver-perl
Plack::Test::ExternalServer.3pm.en	debian 11 / libplack-test-externalserver-perl
Plack::Test::ExternalServer.3pm.en	debian 12 / libplack-test-externalserver-perl