Man pages matching name evp_pkey_asn1_method in section 3ssl:

EVP_PKEY_ASN1_METHOD.3ssl.en	debian 10 / libssl-doc
EVP_PKEY_ASN1_METHOD.3ssl.en	debian 11 / libssl-doc
EVP_PKEY_ASN1_METHOD.3ssl.en	debian 12 / libssl-doc