Man pages matching name anyevent::impl::ioasync in section 3pm:

AnyEvent::Impl::IOAsync.3pm.en	debian 10 / libanyevent-perl
AnyEvent::Impl::IOAsync.3pm.en	debian 11 / libanyevent-perl
AnyEvent::Impl::IOAsync.3pm.en	debian 12 / libanyevent-perl