Add unit tests for middleware

**Feature request**
It would be great to have export for services.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_export` with default `false`.

Start by locating the middleware implementation and its existing unit tests, then trace how configuration options are defined and consumed. Add coverage for the new enable_export option, including its default false value and enabled behavior. Done means the tests clearly verify the requested export path, although the issue does not specify which services or files are involved.

Written by the indexing model from the issue text.