@MaryK1's answer is correct.
Here's the NJ law stating that income earned for services performed in NJ is taxable by NJ, even if you are a non-resident at the time you receive it: https://law.justia.com/codes/new-jersey/2009/title-54a/section-54a-5/54a-5-8
**Answers are correct to the best of my ability but do not constitute tax or legal advice.
