Think I see where you’re stuck. The make changes to a think workflow is meant for changing things that currently exist in the database. Rather, what you want to use is the “Element Actions” > “Set State” workflow.
I made this video a while back that may provide some guidance…
With a custom state, it’s good to think of it like putting a bookmark inside of a book. It’s incredibly helpful once it’s placed on a page. But it’s not actually altering the book (nothing is created). And, as soon as you remove the bookmark and close the book (ie. refresh the page), the bookmark has lost contextual value.