[BUG] Functions executed in separate thread not working due to RuntimeError: Working outside of application context

[Aadesh-Baral]

Describe the bug
When executing a function on a separate thread that requires access to the Flask application context, the implementation was changed to use current_app instead of creating a new Flask app using create_app() with #5642. However, this change resulted in a RuntimeError with the message Working outside of application context.

This error is raised due to the use of current_app outside of a Flask application context. Flask's current_app is a proxy to the current active application instance, but it requires an active application context to function correctly.
While using current_app outside of an application context, Flask cannot determine the active application instance, leading to the error.