402 is not an error. It’s the payment step — always retry with a payment
credential.Base URL
Overview
The retry body must be byte-for-byte identical to step 1 — the server
checks the SHA-256 digest from the challenge.
Pay per request with the Machine Payments Protocol (MPP) — no account or balance required.
402 is not an error. It’s the payment step — always retry with a payment
credential.