shipping tax

So I have many shopify websites and most are dropshipping. This website was a test store and I sold something to Canada. My store doesn't say anything about the recipient or sender paying custom duties and taxes. Should I pay the custom taxes and duties or do the recipient usual pays that...

Wanted to see if anybody has a script that can pick this up or they have access to the list of zip codes set up by county for the state of Maryland. I need this for an ecommerce site that has to deal with shipping tax in Maryland.