I have tow package. Not sure what you mean by shackle hitch. Do you mean the things where the safety chains go or is there something that goes into the receiver hitch?
There is a link there in my previous post. It goes in the hitch receiver and has a d-ring so you can safely connect to your tow strap. It works very well and some folks add it for that off road look. I keep mine by the spare tire until I need it.