IMPERSONATION_READ_ONLY
HTTP 403No
Support impersonation session is read-only — mutating the customer's account (top-up / keys / routing / config) is blocked. Use the dedicated admin tools instead.
By default a failed call returns a result with an error instead of throwing, so your business flow is never interrupted.
Published error codes are permanent: their meaning never silently changes, and deprecated codes keep returning for at least 12 months.