Currently, when using the "3scale application create/apply" toolbox command for applications to both create and update applications it's not possible passing custom values to the parameters client_id and client_secret. Due to this limitation customers are not able to set these both values when using the 3scale Jenkins shared library.

As workaround, but only for Toolbox and not when using the Jenkins shared library, we can use the 3scale application apply command as:

podman run toolbox 3scale application apply --application-key=<CUSTOM_CLIENT_SECRET> --name=<APP_NAME> https://<ACCESS_KEY>@<ADMIN_PORTAL_DOMAIN> <APPLICATION> --plan=<PLAN_ID> --service=<SERVICE_ID> --account=<ACCOUNT_ID> 

Then the client_secret will be set with the value of "--application-key=<CUSTOM_CLIENT_SECRET>" and the client_id will be set with the value of <APPLICATION>. This workaround will be valid only when the Application doesn't exist.