rest api to reject expense

Currently, the expense auditor has a large number of expense reports to approve/reject. Is there a REST API/web service that can reject expense reports and also leave a comment explaining the reason for the rejection, so the user can understand why their expense report was rejected?

REST API for Oracle Fusion Cloud Financials - Process a workflow action

always returns N

REST API for Common Features in Oracle Fusion Cloud Applications - Retrieve a Task

return  "Identity service cannot get users when identities size crosses limit   Fix: verify server log to find the problem cause"