Man pages matching name net::oauth::signaturemethod::rsa_sha1 in section 3pm:

Net::OAuth::SignatureMethod::RSA_SHA1.3pm.en	debian 10 / libnet-oauth-perl
Net::OAuth::SignatureMethod::RSA_SHA1.3pm.en	debian 11 / libnet-oauth-perl
Net::OAuth::SignatureMethod::RSA_SHA1.3pm.en	debian 12 / libnet-oauth-perl