Man pages matching name gnutls_oid_to_ecc_curve in section 3:

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