Navigating inside website and taking screenshot through code

• I need to take screenshots of multiple separate shopping websites for the final checkout page.
• All selections of items in cart and other navigation to pages must be through code.
• The output screenshots should be in image file(jpg,png) or inserted in a docx file(if possible)
• What tool and technology can I use for this task?

I have a little idea about screen capture through php and phantomjs but for a static webpage only. I am a newbie and would be happy if someone guides me here.