SAP Cloud Integration with Concur using REST APIs

Hi,

I am trying to get Vendor data from SAP Concur using its REST API from SAP cloud integration. For this, I am using HTTP adapter with the below connection details.

Credentials used

I am able to get the vendor data via postman. However, I am getting an error when I test my integration flow.

com.sap.it.rt.adapter.http.api.exception.HttpResponseException: An internal server error occured: Status code:400; Reason:{"error":"invalid_client","concur-correlationid":"31ef238e-a3bf-4f67-a248-cddc18af937f","error_description":"unsupported request format","code":135,"geolocation":"https://us-impl.api.concursolutions.com"}.

Appreciate any inputs.