post https://api-v3.authenticating.com/identity/business/verification
The FEIN Verification function is used to verify a business's details, i.e., FEIN, DUNS Number, Business Name, and whether the user is a Business Contact.
All API parameters except DUNSNumber are mandatory.
The result of this API is reflected in the Get Test Result object, under the "FEINVerification" JSON key.