FaceTime App on my iPad is showing a red number 1, what does this mean and how do I get rid of it.

It means you missed a call. If you open the app, you should see a list of recent calls on the left. Once you've opened the app, the badge should go away.

I Had the same problem. In the app go to audio tab, then open the ones in red. Once you exit the number will go away

Same issue here. I tried to follow the suggestion and open the entry in the missed calls list, but when I tap it, a new FaceTime call Is triggered. I do have to delete the entry by swiping left and tap "delete" to get rid of the red circle.