Submits the factor-specific proof and, on success, grants a new 180-day SCA session for the business. Any prior active session for this business is revoked. — Required body fields per factor: sms needs challengeId and code (6-digit numeric); totp needs code (6 numeric digits or XXXXX-XXXXX recovery code); passkey needs origin and credential. — Before KYB approval the session is dormant: it counts for factor enrolment (TOTP setup, passkey registration and import start need a login within the last 15 minutes) but unlocks no account reads or transactions, and its 180-day validity starts when KYB is approved. After approval the session is active immediately.