Enes You have to use the PSD2 certificate (cert.pem) as value for client_payment_service_provider_certificate
and client_payment_service_provider_certificate_chain
in the POST JSON to /v1/payment-service-provider-credential
It's indeed very confusing because you have the client RSA keys (client_private_key.pem and client_public_key.pem) and the PSD2 key and certificate (key.pem and cert.pem) π