NY death certificates are not available to the general public.

For New York City (which includes both Brooklyn and Far Rockaway):

Spouses, domestic partners, parents, children, siblings, grandparents, and grandchildren can obtain the certificate and the cause of death.  Nieces, nephews, aunts, uncles, great grandchildren, great-great grandchildren, grandnieces and grandnephews, can obtain the information needed to do your genealogy, but without the cause of death.  Other relatives are out of luck.  See https://www1.nyc.gov/site/doh/services/death-certificates.page for more specific criteria.

To order, go to https://www.vitalchek.com/death-certificates/new-york/new-york-city-dept-of-health-and-mental-hygiene?click_id=855402888016363522&ppc=0

For all other cities, towns, etc., in NY State:

If you are immediate family (parent, spouse, child, or sibling) or have a legitimate medical or legal need, then you can order them online.  If you are a more distant relative and want them only because you are curious about your genealogy, then you cannot.

To order, go to https://health.ny.gov/vital_records/death.htm