From October 2019 non residents traveling into New Zealand will require an Electronic Travel Authority (ETA). Application for an NZ ETA is a simple 10 minute on-line process. Use this link to access the Immigration NZ ETA information and application web page:   

https://www.immigration.govt.nz/new-zealand-visas/apply-for-a-visa/about-visa/nzeta

This brings New Zealand into line with the USA and Canada for travel authority for inbound travelers coming into the country from partnered Visa Waiver countries (USA & Canada, etc).