Well, you can. You just need to attach the accessory to a lego piece that suits your fancy, and you're done.
https://www.lego.com/en-us/page/static/pick-a-brick
Still, in a world where 3D printing is sold as a happy path solution to everything, putting glue on a couple of COTS plastic pieces sold for about $0.10 seems like an absolute no-brainer.
