Authorize call for https://openbank.apigee.io fails

[#1]

I am trying to run some tests against the various open banking APIs on https://openbank.apigee.io. I guess first question, is this still being maintained? I know there is a GitHub repo to build this out in my own environment but at the moment I would just like to test an end user app against the pre-built environment.

I am stuck on doing the initial authorize.. so

https://openbank.apigee.io/oauth-v1-0-1/apis/get/authorize

I testing from the above link and am keeping the request as basic as possible, this is the JWS and associated values set in the HTTP params.

{"iss":"https://api.openbank.com","response_type":"code id_token","client_id":"GCS7Ccr9TBoA0PUCgaoIidpLPS9k3iIa","redirect_uri":"http://localhost/","scope":"openid accounts","state":"af0ifjsldkj","nonce":"nonce","claims":{"id_token":{"openbanking_intent_id":{"value":"urn:openbank:intent:accounts: 987654321","essential":true},"acr":{"essential":true}}}}

With these details I get the following error:-

{
  "fault": {
    "faultstring": "Execution of ServiceCallout Service-Callout-Validate-Account-Request failed. Reason: ResponseCode 400 is treated as error",
    "detail": {
      "errorcode": "steps.servicecallout.ExecutionFailed"
    }
  }
}

Appreciate any pointers on this!

Thanks

Anthony.