Why is my online store's payment processing always resulting in an error?

Hello,

I was about to launch my online store and when I proceeded to a test payment, it turned out the payments all results in error. The payment provider page shows up, I can choose one of the payment methods, I can enter my payment information and once I click on the “validate the payment” button, it brings me back to the payment page with a single error message : " an error occurred during the payment processing, try again or chose a different payment method".

  • I have tried 5 different payment method, same result.

  • I have checked with my payment provider : no problem on their end, demo payments work fine on their platform

  • I have contacted Shopify : no problem coming from them

  • I have tried uninstalling and reinstalling my payment provider app (kg inicis), I have made sure every Key and code matches.

  • My currency matches the one of my payment provider.

  • My delivery is all set.

  • I made sure the vendor names on product matches the name that appears on the payment provider identification of my business.

  • I have cleaned every cache and cleared every cookies.

I am desperate to understand what Is wrong so I can fix it asap.

Any insight would be greatly appreciated.