Third-party providers like secupay also offer specialized plugins for xt:Commerce 3 that support PayPal alongside other German-preferred payment methods.
Depending on your version of xt:Commerce (from legacy 3.x to the current 6.x), different modules are available: paypal xt commerce download
Modern PayPal modules for xt:Commerce have evolved far beyond a simple "Buy Now" button. paypal xt commerce download