There is no real way to mount a sling mount to the stock. The best option would be to either attach a sling mount to the actual firearms receiver or use the slot on the bottom of the stock to slip through a fabric sling end.
I used the Magpul M-Lok QD mount just fine. Mounted on either one of the 2 slots along the top (buffer tube) and match with your single point Magpul QD sling.
But it says that it does have a sling mount in the description