Call REST service in CAP project using destination with OAuth2JWTBearer

[simonblaser_haufe]

Hi community,

lately I tried to connect a REST Service to a CAP project in order to put a fiori elements app on top of the REST service.
My solution was to proxy the data according to this blog: https://community.sap.com/t5/technology-blogs-by-sap/convert-rest-to-odata-through-a-proxy-service-u...

It seems to work for destinations with NoAuthentication. The destination I want to use has the authentication OAuth2JWTBearer. 
Trying to call the service results in the error message: Error during request to remote service: Failed to load destination. Caused by: No user token (JWT) has been provided. This is strictly necessary for 'OAuth2JWTBearer'.

Is there a solution to firstly get a token and then pass it in every request using this service?
At the moment I did not master it to retrieve any data from the destination.

If there is missing any information, feel free to ask.
Thank you in advance!

[gregorw]

Does the REST service you're using have a public documentation? Who is triggering the Service call? If it isn't initiated by a user no User Token will be available. Then you need to check if you can use OAuth Client Credentials instead.

[simonblaser_haufe]

Hi Gregor, the API is documented here: https://api.sap.com/api/SAP_CP_Workflow_CF/overview Via the the destination I mentioned I was able to retrieve data in an other nodeJs application.