If you've lost the batch file to import to your accounting system or need to import again, go to Organization Billing > Posting: Posted by Batch > click on "Recreated Posted Batch File".
A pop-up will appear where you can enter in the batch number. Enter in the batch number of the batch you'd like to re-generate. Only one batch can be re-generated at a time, so if there are multiple batches, repeat the process.
Once you click on submit, the file will re-generate and download for you to use.