Nfc in my iPhone 7+ can't work

Hi Edwardfir, We appreciate you reaching out to us. If you are unable to use the NFC at all, please check for a software update and make sure that you are running the latest version of iOS.

While it isn't inherently assured that an update will resolve the issue, updating to the latest software version for your device can help isolate potential software issues. 

Kindly secure a backup and update.

1. How to back up your iPhone, iPad, and iPod touch
2. Update your iPhone, iPad, or iPod touch

If the issue persists, please have the device inspected by a technician.

You can explore your service option here: Get Support

Take care!