Man pages matching name gnutls_sec_param_to_symmetric_bits in section 3:

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