Hi everyone!! iam getting the next error when i try to use X509.PrivateKey.to_pem

iex(174)> X509.PrivateKey.to_pem(priv, [password: pass])
** (FunctionClauseError) no function clause matching in X509.PrivateKey.pem_entry_encode/2

The following arguments were given to X509.PrivateKey.pem_entry_encode/2:

    # 1
    <<48, 130, 5, 14, 48, 64, 6, 9, 42, 134, 72, 134, 247, 13, 1, 5, 13, 48, 51, 48,
      27, 6, 9, 42, 134, 72, 134, 247, 13, 1, 5, 12, 48, 14, 4, 8, 2, 1, 0, 2, 130,
      1, 1, 0, 2, 2, 8, 0, 48, 20, ...>>

    # 2
    '12345678a'

Attempted function clauses (showing 7 out of 7):

    defp pem_entry_encode({:RSAPrivateKey, _, _, _, _, _, _, _, _, _, _} = rsa_private_key, nil)
    defp pem_entry_encode({:ECPrivateKey, _, _, _, _, _} = ec_private_key, nil)
    defp pem_entry_encode({:PrivateKeyInfo, _, _, _, _} = private_key_info, nil)
    defp pem_entry_encode(private_key, password) when is_binary(password)
    defp pem_entry_encode({:RSAPrivateKey, _, _, _, _, _, _, _, _, _, _} = rsa_private_key, password)
    defp pem_entry_encode({:ECPrivateKey, _, _, _, _, _} = ec_private_key, password)
    defp pem_entry_encode({:PrivateKeyInfo, _, _, _, _} = private_key_info, password)

(x509 0.8.5) lib/x509/private_key.ex:281: X509.PrivateKey.pem_entry_encode/2
(x509 0.8.5) lib/x509/private_key.ex:158: X509.PrivateKey.to_pem/2
iex:174: (file)