From a web browser, login to your nytimes.com account via your current login method (eg. email/password or social login method). Then go to Account > Account settings > click "Manage" next to Connected Accounts / Work or School.
Account:

Account settings:

Connected accounts:

OR
Existing NYT program subscribers can continue to visit nytimes.com until their academic passes expire after 4 years, after which they must visit nytimes.com, click Login, then scroll down and click “Continue with work or school single sign-on” at the bottom of the login page (as shown above in the New User section).