Product preview on the admin page in the product catalog.
installation:
1. extensions -> installer. upload file preview_product_in_the_admin.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 Catalog -> Products

Order preview product :
https://www.opencart.com/index.php?route=marketplace/extension/info&member_token=NDEPw9P5LVJ3DXSq7amxWMObkOYpvb9t&extension_id=40971