Add parameter to wordpress xmlrpc?

We have a 3rd party system we use to make new posts on our wordpress install. See: http://codex.ww.wp.xz.cn/XML-RPC_WordPress_API

My question is how can i include the new passphrase with the password so it can actually create posts?

Thanks in advance.

https://ww.wp.xz.cn/plugins/stealth-login-page/