Login and Pay with Amazon Problem

I am using version 2.0.3.1. I have an SSL install and working fine. I am trying to use Login and Pay with Amazon, but it isn't showing up at checkout.
I have all the API keys set properly (Merchant ID, Access Key, Secret Key, Client ID, Client Secret).
Payment mode is set to "Payment" (have also tried "Authorization" and still didn't work).
Marketplace is set to "US"
Automatic Capture Status is set to "Complete"
Pending Order Status is set to "Pending"
Secret Token is set
Minimum Order Total is set to $1 (tried checking out with over $4 and it didn't work)
Geo Zones is set to "All GEO Zones"
Debug Logging is set to "Disabled"
Status is set to "Enabled"
Test Decline Codes is set to "No"

On Amazon's side, I have filled out the application for the Client ID, added in my bank account, credit card for charges, IPNs URL and everything else that is required.

My question is this, why isn't it working? Is it bugged? Any and all help will be greatly appreciated!

Hi sorry I am new so not yet able to help you. I am actually stuck on "Client Secret" where to get this from?
Any help is greatly appreciated

Thanks
Jessica