You need to buy a M-LOC picatinny rail and then you can buy any front plate that mounts to a picatinny. I use the targetshooters.com A-3 Bag Ryder. Should get you where you need to be.
Just attach the plates of choice I attached a arca rail to mine, the plate or attachments should come with the M-loc style T-nuts (If that’s the correct term for fasteners?)