How can I pass the password for the private key in the kafka_group input plugin.

Good afternoon.
How can I pass the password for the private key in the kafka_group input plugin.
I can't find any mention of password transfer in the documentation.

Example of the expected option:

```

@type kafka_group
brokers kafka:9093
consumer_group kafka-group
ssl_ca_cert ca-cert.pem
ssl_client_cert client-cert.pem
ssl_client_cert_key client-cert-key.pem
ssl_client_cert_key_password password
topics kafka-topic
format json

```

thank you in Advance.