HI @TravisM1 !
You will find the solution to this problem. I am going through the same situation.
Thank you so much.
Greetings!
Topic summary
A newly launched Shopify store cannot process credit card payments via Authorize.net. Despite configuring the third‑party gateway, Transaction Key, and API, Authorize.net is not registering any transactions, while Shopify returns error codes “E00028” and “E00007” and shows a generic payment failure message to customers.
Attempts by both the merchant and customers result in the same error: “There was an issue processing your payment. Try again or use a different payment method.” The merchant asks how to correctly connect Shopify with Authorize.net.
Another participant reports experiencing the same issue and is looking for the solution.
Technical note: “E00028” and “E00007” are Authorize.net error codes surfaced by Shopify; their specific meanings were not discussed in the thread.
No troubleshooting steps, decisions, or fixes were provided. The discussion remains open with unanswered questions about configuration/authentication and why Authorize.net is not receiving the requests.