Using Amazon Pay, need access token in return call


#1

How can I get the Access token after making a payment using the Amazon Pay Express Button? It is only returing the following details:
http://www.courtandcherry.com/AmazonResponseHandler
?resultCode=Success
&orderReferenceId=S01-0912345-1234567
&sellerId=ADEMO3053M41F7TEXAMPLE
&accessKey=ARIWE420982EXAMPLE
&amount=10
&currencyCode=USD
&paymentAction=None
&sellerOrderId=A481WEIFEXAMPLE
&signature=n345ngiwasdfasdJimCJixkEuxqN0021sdf56bDdZ4EXAMPLE