I’m afraid you need to be a NJ resident and have a relationship with a NJ doctor who is enrolled in the state’s program to purchase cannabis from a dispensary there. Here are a few lines straight from the NJ state website. Sorry!
I possess a medicinal marijuana patient card from another state; may I use it in NJ to obtain medicinal marijuana?
No, to be eligible for the New Jersey Medicinal Marijuana program you must:
Maintain a bona fide relationship with a New Jersey physician who is registered and approved by the MMP and,
Be certified with a debilitating medical condition by the approved NJ physician and,
Be a New Jersey resident.