I think you are missing the basic part over here. You have modified the document but you need to save it too.
If you would have noticed after you had made changes to the document. Its state would have been updated to ‘Modified’ from the previous state which could be ‘Unused’ or ‘Original’.
Now you need to send a PUT request, once the PUT request is processed for the requested document, then the change (data source of the data provider) will be updated in the repository as well.