Hi,
Set your PayPal account up in web.config or user.config then you see PayPal payment link in cart page.Find the following settings in web.config or user.config file:
<add key="Site1-PayPalSandboxAPIUsername" value="" />
<add key="Site1-PayPalSandboxAPIPassword" value="" />
<add key="Site1-PayPalSandboxAPISignature" value="" />
<add key="Site1-PayPalStandardSandboxEmail" value="" />
<add key="Site1-PayPalStandardSandboxPDTId" value="" />
<add key="Site1-PayPalProductionAPIUsername" value="" />
<add key="Site1-PayPalProductionAPIPassword" value="" />
<add key="Site1-PayPalProductionAPISignature" value="" />
<add key="Site1-PayPalStandardProductionEmail" value="" />
<add key="Site1-PayPalStandardProductionPDTId" value="" />
Hope Helps,
Asad