Your Point-of-Sale should generate QR code.
Online mode
If you have UID, than you should set this target url with UID:
https://ecitizen.firs.gov.ng/en/payment-code-verify?code={UID}
Example:
https://ecitizen.firs.gov.ng/en/payment-code-verify?code=42a8bcd3-0af1-55fd-9d4b-260f915e4f99
Offline mode
If there is no Internet connection and it is not possible to get the UID, then only the SID will be printed on the receipt/bill. QR code should have all important elements:
https://ecitizen.firs.gov.ng/en/security-code-verify/{VAT ID}~{Bill number}~{Office ID}~{Device number}~{Datetime}~{Total}~{SID}
Example:
Please put QR code below this sentance (without quotes):
“Check if your receipt is valid”