Anyway

WWW-Authenticate: basic realm="Remote User Access"

Yeah that doesn't mean that "@headers " stuff

See https://metacpan.org/pod/distribution/SOAP-Lite/lib/SOAP/Transport.pod#HTTP-BASIC-AUTHENTICATION, https://metacpan.org/pod/LWP::UserAgent#get_basic_credentials, https://metacpan.org/pod/LWP::UserAgent#credentials