Redirect from Shopify Starter to 3rd party site for purchase

[IEA]

Hi. Looking for some advice on customising the checkout for a Shopify Starter shop please-

Rather than going through the checkout on Shopify, I would like:

1. A redirect from the “Buy” button to a 3rd party site (Amazon), for customers to go through the checkout on there
2. The standard Shopify checkout to be hidden (as the purchase takes place on Amazon)

Would appreciate any guidance on how best to do this?

Thank you!