I wanted to replace an interior door in my home so I bought one of those 6-panel pre-formed slab doors. I bought a new door handle and hinges also.
The door is made out of some type of plastic/fiberglass/foam material.
I got the tool to attach to my drill to cut out a hole for the handle and lock.
However…
When attaching the new hinges to the door,
how do I go about countersinking them into the door?
Is there a tool made that makes a cutout on the door for the hinge plate to sit into?
Two ways: Either with a router and a special template, or with a chisel (trace around the hinge, chisel out a notch for the hinge to sit in).
First timers for either of the above are urged to practice on some scrap pieces of wood prior to approaching an actual door, unless they fancy the ‘rabid beaver’ styling. 
CAUTION be sure the solid plastic shell is thick enough to rout out.
Did hinges come with the door sections? If so were they about 3/32" thick and fit into one anoter or are they butt hinges? Usually a set of six panels for folding doors comes with hinges, screws or other fasteners and instructions. The are installed without routing or recessing due to being thin.
Routing the plastic is bad enough but trying to chisel out recesses in plastic and have a neat job is virtually impossible.
If you bought them at the Big Blue L Box or the Big Orange HD Box you should check back with them for possible missing parts/instructions.
To do this properly (meaning safely and neatly) really requires a router and jig for controlling where the router can go.
If you haven’t made any holes in the door you bought, I’d advise returning it and the lockset hole saw and getting a pre-hung door. Then, you just take the trim off the old door frame, remove the old door and its jamb, slide in the new door, shim and adjust so it’s square, nail it in, then put on the trim and install the lock. No drilling or countersinking required.
I feel like an idiot. I read the title of the thread and thought that the OP wanted advice on questioning his door hinge. I was going to suggest keeping it awake for a few days and not feeding it. After that it’d tell you whatever you want to hear.
In Soviet Russia, door hinge questions YOU!!
Jack Bauer can make your door hinge answer questions!