Basically the title, you need to use the skills you have now and be a productive member of society.
I don’t mean go back and show the wheel or try invent germ theory etc.
For example I’m a mechanic i think I could go back to the late 1800s and still fix and repair engines and steam engines.
Maybe even take that knowledge further back and work on the first industrial machines in the late 1700s but that’s about it.
I can dig a hole in the earth so I’d say my skills apply all the way back to Ur and Sumeria.
Can you do it without a shovel? Even if hard packed? What if there’s a rock too big for you to lift?
You could go all the way back to dinosaur times when we were burrowing rodents