Man pages matching name rt::client::rest::httpclient in section 3pm:

RT::Client::REST::HTTPClient.3pm.en	debian 10 / librt-client-rest-perl
RT::Client::REST::HTTPClient.3pm.en	debian 11 / librt-client-rest-perl
RT::Client::REST::HTTPClient.3pm.en	debian 12 / librt-client-rest-perl