Man pages matching name gnutls_sign_algorithm_get_client in section 3:

gnutls_sign_algorithm_get_client.3.en	debian 10 / gnutls-doc
gnutls_sign_algorithm_get_client.3.en	debian 11 / gnutls-doc
gnutls_sign_algorithm_get_client.3.en	debian 12 / gnutls-doc