Integrating PayPal's smart button into Shopify without specifying the price or shipping rates.

[Emma-H]

Hello,

I'm wondering if there's a code that could help me integrate the PayPal smart button to my Shopify store. I want it to be like this exactly, but when I go to create a button on PayPal, I'm asked to specify the price of the item & shipping rate but I have 160 different products on my store with 11 different sizes for each one with different shipping rates for every size. 

Keeping in mind that I'm not that tech savvy, so I'd appreciate it if there's a code that I could send to the developer working on my store to add the code into my shop. Thank you so much!