I CAN'T GET FORMAT OUTPUT

Your question is rather confusing, to say the least!  Please give us a lot more detail of what you are trying to achieve.

In your screenshot you seem to have two tracks, which I assume you are wanting to mixdown to create a single track.  Is that correct?  If so, where you have selected Export you need to go (click on) to Multitrack Mixdown and then choose one of the options offered there.

Or have I completley misunderstood?