You will need to get under the truck and remove the rest of that stud from underneath if you're lucky enough to have a piece to grab with vise grips.
You can go buy the 2018 version that stimpy433 posted. I went to home depot and bought a stainless steel bolt the same length, a nut and lock washer and a wingnut. I ran that up through the bottom then put a nut on from the top under the seat to lock it in place then secured the jack to it with the wingnut.
The whole reason I did that instead of the 2018 part from the dealer is it takes me 20 or so minutes to get to the dealer but only 3 minutes to get to home depot. Also I bought a shorter stainless steel bolt because there is another threaded hole about 6 inches in front of that and water, road salt etc can get in through that and rot the floor through eventually.