Error while calling DATAFLOW SCHEDULE REFRESH API...

I created an application in the azure active directory and created a secret principle for it. And I created a new security group and added the new applications secret as a member. And these pre-requirements are for calling a rest API on power Bi.
I then added the security group to the required workspace by assigning a role as admin in the workspace, so that the app can able to edit the objects in the workspace.

Coming to API calling with the app, everything went fine like dataset and group level except DATAFLOW level.

Coming to the Dataflow level, refresh API works fine but schedule refresh API is returning an error, and the status code of error is 500 and the message of the error is "An error occurred."

And the same thing happened for Dataflow update API" also does not work with service principle and returned an error and the error message for this API is "DataflowUnauthorizedError".

Note: we should not use a username and password for calling API.

Please Help I tried my level best But it is taking a too long time.

#Developer @RestAPI