I'm assembling a bike trailer and I don't know how I'm supposed to attach the reflectors.

The instructions are in Dutch only and only seems to mention that reflectors exists but gives no instructions on how to put them on. The only directions are the grainy photo on the box, showing something that looks like reflectors being attached to the fabric of the cover.

The reflectors themselves (two white ones and two red ones) have a short screw and nut as well as a short protruding plastic pin on the back.

There are no holes or similar obvious way of attaching the reflectors. Am I literally supposed to poke holes in the fabric myself?

Edit: Jesus Christ, they literally poked two small holes in the fabric to attach the reflectors. Aren't the Dutch supposed to be good at bike stuff?