You don't find it because Jabber Voice is no longer available, Jabber for iPhone/Android is the replacement, it was never tested with iOS 9, so, there is no way to tell you if it should work, or how to make it work, it's officially not supported on that iOS version.
You can configure Jabber for phone only, it's the exact same thing as J4W, you control whether it's IM only, full UC, or softphone only via the service profiles.
HTH
java
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