The registration process is a "demo" and has no relation\link to the TPPs Open Banking user credentials.
Our ASPSP details:
ForgeRock Financial ID: 0015800001041REAAY
As a developer, you would like:
Forgerock Sample codes: https://github.com/ForgeRock/ForgeRock-OpenBanking-Sample
ForgeRock Open Banking Datamodel SDK: https://github.com/ForgeRock/OpenBanking-Java-SDK
Open Banking books
All the blogs articles wrote by ForgeRock around their Open Banking platform.
All the news related to the Open Banking platform
All the articles to help you troubleshooting your issues.