The items will ask you for gunpowder, which you can make in the Gunpower Workshop.

You will also need blueprints that you can receive after exchanging objects for blueprints, the latter you can do from the selection of a dweller and the "equipment" option that you will see. Once you click on the objects, you will see the option to exchange them for a defined number of blueprints and thus you will be able to find the creation you need.