Compiler error & file call back not supported

[frangio]

Please refer to our guide on verification. @Shuaib_Akoh Next time search before posting!

How to verify a contract on Etherscan/BscScan/PolygonScan

Make sure to read this post before asking a question about verification. If your issue is not addressed here, just leave a comment below. If you want to pay someone to do the verification for you, create a post in Smart Contracts > Developer Wanted. This guide applies to all Etherscan instances, including all of the following as well as their testnet explorers: etherscan.io (Ethereum) bscscan.com (Binance Smart Chain) polygonscan.com (Polygon) snowtrace.io (Avalanche) Recommendations Prac…