Man pages matching name soap::transport::loopback in section 3pm:

SOAP::Transport::LOOPBACK.3pm.en	debian 10 / libsoap-lite-perl
SOAP::Transport::LOOPBACK.3pm.en	debian 11 / libsoap-lite-perl
SOAP::Transport::LOOPBACK.3pm.en	debian 12 / libsoap-lite-perl