Macro Lens Nikon D3400. It depends on what you want to do there are optical and mechanical solutions too getting closer either alter lens or move the lens further from the film plane. Web view on amazon.
At this time, we have details of 26 macro prime lenses which will suit the d3400. Web ultimaxx 55mm complete lens filter accessory kit with 55mm 2.2x telephoto.43x wide angle/macro lenses, and more designed for nikon d3400 d3500. (such as d3000, d5000, and d7000 series), i think that the 85mm macro lens.