Where is the Entity Procedures option?

so i was making a enchantment for my chestplate but there is no option as entity procedures (iam making a new enchantment and after that i need to make a new procedures so in that the option is not there) so can anyone show me where the option is? also i cant as well find this block of code 
Set Movement vector to vx (default number 0) vy (0) vz (0)
pls reply, thanks for reading this.