An export of existing Conversion Request is using the same format that you can also use for imports. Have a look at this article to learn more about this feature.
Go to the Conversion Request Explorer and use the filter panel in order to restrict the view of shown Conversion Request by creation date, request type, request status, or other criteria.
After you have finished your selection, you can export these Conversion Requests by click on the export button
Your export will be performed in the background and you can download the file in the Conversion Request Export section.