Good luck mounting that on a plastic body. And since he's not age verified he can't get access to a metal body good enough to mount the rail on. However, you can find a AK mount that mounts just in front of the mag well. At worst you'll need to find longer screws.
Ak top handguard rail is the most practical and easiest to find.
Every word ever written will fall short, of it's intent
Even sung, or spoke, or screamed, they will betray what they had meant.