Take a look at this tutorial series: You will have to add a slot with the slot name, which you have added in the montage, between the state and the final pose in your anim graph 
→ in your case FullBody
Take a look at this tutorial series: You will have to add a slot with the slot name, which you have added in the montage, between the state and the final pose in your anim graph → in your case FullBody