We've been using SIM (I guess now renamed as Payment Form) for several years.  The BIG advantage of this method is that it falls under PCI SAQ A, which is easy to meet the requirements.  I would keep using SIM forever if the payment page was made responsive.  Not sure why that was so difficult and never got done.  

So, it looks like the "Accept Customer Hosted Form" (previously CIM Hosted?) is the place for me now, even though it is much more complex than SIM.  Still falls under SAQ A if I use a redirect or iframe.  

I copied the sample code from here: https://github.com/AuthorizeNet/accept-sample-app and it mostly works.  The part I'm having trouble with is the button labeled "Hosted Pay".  That button posts  to https://accept.authorize.net/payment/payment, and uses a method "getHostedPaymentPageRequest".  

Where is the documentation for  https://accept.authorize.net/payment/payment and getHostedPaymentPageRequest?  I can't seem to find any mention of these.  

When I run the sample code, I receive this error message:

"Error E00001 An error occurred during processing. Please try again."

Any ideas what to try to make this work?

All the other features work fine.  I'm using our live account, not sandbox.  

Thanks.

Bob