What version of Facebook has the Microphone feature... Where you can have the phone pick up on,what

I'm not sure that Facebook has public version numbers, if you update your mobile app to the latest version it should have it.

I have the latest version. It isn't on there. I have been uninstalling older versions of Facebook. It doesn't work.

Features are not uniformly enabled for every user and/or location. Some will be put in tests to try out different layouts etc. There's nothing you can do other than update to latest versions to get the feature so short of it not working as you think it does there's not much I can suggest to you.