post https://secure.nmi.com/api/v4/merchants//security_keys
Never Use Real API Keys
Never use real API Keys when testing. The gateway allows Partners to create Test Merchant Accounts. Testing should always use keys from the Test Accounts and never keys from a Standard Account.
Usage
This request will create a new API key for a user on a merchant account. The request includes all key types, including those for the Payment API, Query API, Collect.js, and Collect Checkout.Sending User ID
The `userId` is optional, and will default to the primary user on the account if it is not provided.A full list of user IDs on merchant accounts can be queried via Get Merchant or Partner User Info.