TPPs have to authenticate towards the PSD2 APIs that ASPSPs provide using certificates and (in some cases) TPP credentials.
finAPI Access supports the following two authentication scenarios:
licenced AISP/PISP can upload their certificates and credentials to finAPI Access and access PSD2 APIs using their own certificates and credentials
unlicenced clients that use the finAPI PSD2-Licence / Web Form can access PSD2 APIs using the finAPI certificates and credentials
For a detailed description on what you have to do as a TPP, please refer to pages in this section: