Re-installing El Capitan on a early 2015 MacBook Air
I recently decided to get my wife a new MacBook Air. I had decided to trade in her old early 2015 MacBook Air and erased everything off of the hard drive. Now my wife informs me that she wants to sell it to a friend for the same trade in value. I am not having any luck re-installing El Capitan. I start it up in recovery mode. When the window comes up for me to select what to do, I select re-install OS X. It goes through the process of checking with Apple to see if it is authorized. Then a window comes up asking where to install El Capitan. But there is no location shown, no hard drive - it's just blank. I've tried all the above several times and get the same result. How can I install an operating system on this MacBook Air?
MacBook Air