Preview the product on the admin order detail page
installation:
1. extensions -> installer. upload file Order_preview_product.ocmod.zip
2. clear cache in extensions -modification
3. dashboard on the right cogwheel and refresh theme

after successful installation and clearing of the cache, you should see the "view" button next to the edit button in the Sales --> Orders --> order detail

Preview product in the admin link:
https://www.opencart.com/index.php?route=marketplace/extension/info&member_token=NDEPw9P5LVJ3DXSq7amxWMObkOYpvb9t&extension_id=40936