Man pages matching name gnutls_aead_cipher_encryptv in section 3:

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