If your customers are receiving this error on Shopify - "Your payment cannot be processed for technical reasons" - there are a few reasons why this might be happening.
Common reasons for this error
This error is usually caused either by putting in the wrong API keys or putting in the Public Keys in the Secret Keys field and vice versa.
How can I fix this?
To fix this error, please go to your Paystack Dashboard to copy your API keys.
In order to get your Live API Keys, simply go to your dashboard settings and click on the API Keys & Webhooks tab. Scroll to where it says "API Configuration - Live Mode", here you will find your Live Secret Key and Live Public Key as captured below:
After you have copied the keys, kindly replace them on your Shopify Payment Settings, taking care to place the correct key in the correct field.
For more information, please see How to setup Paystack on Shopify