how to use for UPACKNSHIP

I a trying to buy a large amount of bags from the website  

https://www.upaknship.com/custom-mailers.html?p=2

and it says I can customize the logos and printing on them.  but when I go to do so it senbnd me to this site and it seems like a website customizer not a bag customizer.  so I am just confused and woulds appreciate if you could help me figure this out thanks.  

You got it right. They have used our tool to make the form where the logos are. Please try to contact them through their page.