A family of Microsoft word processing software products for creating web, email, and print documents.
There isn't any mirror-image setting within Word itself. Your printer may be able to do it, though.
Press Ctrl+P to open the Print page, and click the "Printer Properties" link. The dialog that opens is actually provided by your printer driver software, so it's different for each brand (and maybe each model) of printer. Look for a setting that says something like "mirror image" or "transfer" or "t-shirt". It might be a checkbox or an entry in a dropdown. If there's a Help button in that dialog, look there for a mention of the setting.