THREEDLOOKUP requestTHREEDLOOKUP responseHTTPS POST to threeDSMethodNotificationURLIf 3-D Secure version 2:HTTPS POST toTHREEDQUERY requestTHREEDQUERY responseIf 3-D Secure challenge is required:Customer’s browser redirected to ACSTHREEDRESULT requestTHREEDRESULT responsecachetokenIncludescachetokenIncludesStep2Method URLStep3THREEDQUERYStep4ChallengeStep5THREEDRESULTStep1THREEDLOOKUPACSMerchanttermurlAUTH requestAUTH responseStep6AUTHthreedmethodurlthreedmethodurlCustomer’s browser redirected back to termurl