anything with the electric force is used by pressing and holding
the circle button. and if you need more help with your force
powers. you can look them up on the rogue shadow. there will be a
section on the ship that says force powers. when you are in that
menu you can upgrade your force powers, and it also telss you how
to use those force powers.
p.s. i just beat the game yesterday so this should be of great
help.