Here’s a link to the info for Germany + fees: https://sell.amazon.de/en/versand-durch-amazon/multi-channel-versand
This might also help for fee calculation if you are already listing on Amazon: https://sellercentral.amazon.com/fba/profitabilitycalculator/index
I used to sell in Amazon Germany, UK, and USA. Was nice we were actually surprised by the Amazon Germany market success. We used inventory there to ship Shopify orders in Germany (I used to manage a Shopify store).
If you want to automatically fulfill your Shopify orders using your Amazon FBA inventory, Order Automator does that and can handle any marketplace + multiple marketplaces if you want to route orders to different Amazon countries.