I set-up everything, and am using Notification Serial Number so my API callback URL is HTTP. Google is reporting an error, saying "We encountered an error trying to access your server at http://mywebsite.com/amember/plugins/payment/google_checkout/ResponseHandler.php -- the error we got is Send failed with code: 401. Response body was:" What do I need to adjust to fix this? Please help. Thanks.
I'm getting this same issue, I have verified that my merchant key and ID are correct. I'm not able to use https, does that have anything to do with it? According to step 3 of the integration instructions I'm supposed to: 3. Login into Google as Seller and setup this URL: http://www.presscoders.com/members/plugins/payment/google_checkout/ResponseHandler.php at My Sales -> Settings -> Integration -> API callback URL This URL should be https:// but you can use http:// with sandbox test account.
You must use https url for callback script in live mode. Google will not post notifications to not-secure URL also, notifications will not be posted if your site have incorrect SSL cert installed. Have a look: http://checkout.google.com/support/sell/bin/answer.py?hl=en&answer=134466