In the following example, an ASPSP has chosen to process the SCA methods for the consent approval through the TPP – ASPSP interface. In any case, the PSU normally will need to authenticate himself with a first factor, before any account or SCA method details will be available to the TTP.
In case where an OAuth Pre-Step took place, to replace the PSU credentials by an access token. Also, the sequence of the PSU authentication with the first authentication factor is omitted.
Depending on the ASPSP decisions, the flow may vary, e.g. if only one SCA method available - choosing SCA method step will be omitted.
Sequence Flow
