Client credentials Grant setup (in OAuth 2.0 settings)

To configure the "Client Credentials Grant" for STET, add the plugin "OAuth 2.0 Client Credentials Grant" in the "OAuth 2.0 Settings".

Configure it as follows:

1. Use the following plugins in the list of "Granted Scope Processors":
1. Plugin "OAuth 2.0 Granted Scope Whitelist" with allowed scopes: "pisp" (all other scopes are used with the Authorization Code Flow)
2. Plugin "STET PSD2 OAuth 2.0 Scope Filter" (no detail configuration necessary)
2. As "Signature" use the plugin "JWT Access Token Private Key Signature"