My website already exists. I am trying to integrate one of the pages on my site with my merchant account, First Data. (The current problem appears to deal with a has calculator. For specifics, see Instructions on using the Hash Calculator can be found here: https://firstdata.zendesk.com/entries/407522-first-data-global-gateway-e4sm-hosted-payment-pages-integration-manual#4.7). (The integration instructions are online at First Data, with the specific code included.)
I offer training courses and would like the attendees to be able to register for the course and pay online. I woud also like to be able to update the payment links as course offerings change.
I have had two develoepers attempt this but to no avail. I understand from First Data that this should not be difficult for developers to do.