The NAM API uses Bearer Authentication to authorize requests. As such, you must provide the following HTTP header on all requests, with your API token:

--header 'Authorization: Bearer <token>'

To obtain the API access token for a logged in user and a given account, please login to Nextdoor Ads Manager and head to the settings page to obtain an API token. A user may only have one API token at a given time; the token can also be revoked in the UI from the same settings page. API tokens expire after one year.

The API token gives API callers the ability to take action on behalf of all advertisers that are tied to the NAM account. It also gives the ability to add new advertisers, of which the API based user will automatically be an admin for.