If it is a base model (like mine), then there are no supplied anchoring points under the phenolic coated plywood. I know this, because I removed my floor base when I first purchased my van and checked over the entire floor.
Having said that, I have a bench seat with 3x seatbelts which I've adapted so it can be placed into the cargo compartment with the occupants looking towards the tailgate. It backs onto the bulkhead, and I have it anchoring to that and the floor, so pretty dam solid when installed.
This is for "emergency use only". It is not by any stretch "type approved", and I'm pretty certain that any insurance company would throw a fit at any claim involving my van whilst the seat was in use. Furthermore it wouldn't resist scrutiny from an adequately motivated officer of the law.
Hth