If AltGr is right Alt, it does print a bunch of stuff. On my system, SysRq is under PrtSc. Does that mean I have to do Fn+PrtSc to get SysRq or just PrtSc is enough.
If it prints out without presssing Fn then you're doing it right. Laptop keyboards are weird but usually it's just the PrtScr key as it acts as SysRq when using the Alt[Gr] modifier.