Greetings and welcome to the Forum.
Your machine is a straight die grinder, not a router in the usually understood sense. Nevertheless, it has no-load speeds of 10 000 to 29 000 r.p.m.
It might be possible to find a drill chuck with the corresponding internal thread, but I think it might be unwise to do so. I cannot think that anybody makes a drill chuck which is balanced for those speeds. I have a small chuck for a Dremel tool, which operates at similar speeds, but that is much smaller than your tool.
Might I ask what you plan to use the tool for?