Amazon Pay integration help

Hi,
I hope you guys doing great, I’m trying to integrate the Amazon pay service in PHP application.
I’m really confused by the PHP SDK. I want to charge for subscription. Is there anyone help me with it.

Regards

What code have you tried so far?

Thanks for your reply.
I using some sample code which is available here. I’m a little bit confused about the flow. Like other payment gateways (Paypal) we submit the form to the sandbox and the PayPal system displays the charging amount and we click on the proceed and get IPN. But in amazon’s case, we first get authorize from the amazon site and they not showing like how much charges buyers going to pay. Once the user authorizes it to redirect back to the site and again enter payment method and confirm payment.

This is all which I know but if you can help to share some simple code like Paypal. I will really appreciate your help.