App preview- two problems: sound and first frame.

I made a video for app preview in Final Cut Pro X.
I used printscreens and graphics to make a video.
I had no sound (I think I don’t need it. I don’t have a microphone).
I made two files.
In the first file in ’Master File’ I chose ’Video and Audio’ in the second one ’Video’ in ’Format’.
I added it to the iTunesconnect, but in the both files iTunesconnect shows: ’This video has audio that is not two-channel, no sound stereo’.

Questions:
1.What to do to have no sound in the file from QuickTimer/ Final Cut Pro X and be able to add file to iTunesconnect?
May I add an empty audio path to the QuickTimer/ Final Cut Pro X and it will be two-channel? How to do it?
If I need an audio, where can I find it in the internet (two-channel) are there a web sides with it?

2.I have problem with first frame in the output file.
In my video there are print screens and graphics. FCP chose graphics from middle of the video, but I want first frame from my movie. I shared it three times, and every time it not a first frame from video.
I changed image in the file Info in QuickTime player, like there:
www.fcp.co/forum/4-final-cut-pro-x-fcpx/...ee-on-an-output-file
but it changed nothing. Of course there is a small image I added in info, when I added it to iTunesconnect it shows a frame from the middle.
How do I fix it?

1. Make sure your project setting are set to stereo sound, then export your master file with video and audio.
You may need to add a sound file with the volume all the way down to trick it into exporting an empty audio track.

2. the poster frame is selected inside iTunesConnect after uploading, see Apple's developer guides for more info.
developer.apple.com/go/?id=itunes-connec...er-guide-app-preview

Hope this helps,
-Mark

Your advices was very helpful !
I didn't expect I can choose poster frame inside iTunesConnect.
I red advices on Apple developer side but not there.

I will try to find free sound or make something with my friend.
I have my brother microphone and mixer, he don't use it, so I will try.
I don't know the sound quality from my friend keyboard recorded by the microphone, will be enought.
Maybe there is good connection from keyboard to mixer or to computer.
I think we need a program to record it (he got a PC with windows)
I have device but no knowledge, how to do it.

GarageBand is free, and will record audio from a mic, line-in, or MIDI keyboard.

Anyone with Windows can use Audacity (also free) to record audio, and then export a .WAV file which you should be able to easily import into FCPX.

Audacity works fine with IOS too.......