In 2016 Paystacks lunched their plugin for shopify store owners in Nigeria with which you can receive payment in Nigeria .Here is the breakdown process of Integrating into your store.
Step 1
https://paystackintegrations.com/shopify and Click "Install payment provider" when prompted.
Step 2
Scroll to the "Accept Paystack" section of the page and insert your Paystack Public Keys and Secret Keys in the fields highlighted.
These keys are available on your Paystack dashboard at https://dashboard.paystack.co/#/settings/developer . Click "Activate".
Finally, your store can now accept payments using Paystack
NB: Paystack only processes Naira amounts at the moment so your store prices have to be in Naira for Paystack to work


Source ..>>>> http://geekyfingers..com/2018/08/how-to-integrate-paystacks-with-your.html