What is the Face Time setting for iphone6? Why is it missing?

In the settings, under Information, if not, then access restrictions are enabled. Click "Settings-General-Access Restriction" (below, under the automatic lock), which contains FACETIME.

When OTA was upgraded to the latest firmware, FACE TIME came out.

When using Facetime, we need to have an ID number, and we can use apple id.

Click Settings -Facetime in your phone.

Then you can see the FacetimeID. If you are currently logged in with another apple id instead of our own, we can click on the apple id to cancel and modify it.

Then we can log in and use Facetime to enter the video call.