You need to purchase an item box from the general section of the store. The item box is something you can store things in and send off with the drone to sell the items inside.
Thank you very much. I've only recently started playing this game, but it's great. The only thing is that I don't get the signals very well.
It all comes with time, but if you ever need help, I'm always willing to give more tips and whatnot.
