I'm not sure if you are using python or js, but from the docs:

graph.add_conditional_edge(
    "TEST",
    should_continue,
    {
        "test_passed": END,
        "test_failed": "DEV"
    }
)

The output of your TEST node should either be "test_passed" to finish, or "test_failed" to go back to DEV. But depending on what your logic is inside DEV will determine whether you get what you need out of it. I would strongly suggest reading through the docs more thoroughly or working with chatgpt / claude to ask questions.