You should have gotten a tutorial presented when you got bots, that'll go over over how it works. You can just place ghost items by hand (press shift) but not

You should have gotten a tutorial presented when you got bots, that'll go over over how it works. You can just place ghost items by hand (press shift) but not much point. The advantage is being able to smack down whole bunches of machines in blueprints. They can build anything if the products are in provider chests. They have the exact items, they won't build from intermediate materials.