no API token was found for this network. Please provide one in your hardhat config

[OmarWaqar123]

at 9:10:19 when I'm trying to verify my contract on ether-scan it's continuously throwing this error and I don't know what I'm doing wrong here . hardhat version: "^2.10.0" , "@nomiclabs/hardhat-etherscan": "^3.1.0".

ERROR

NomicLabsHardhatPluginError: You are trying to verify a contract in 'rinkeby', but no API token was found for this network. Please provide one in your hardhat config. For example:

{
  ...
  etherscan: {
    apiKey: {
      rinkeby: 'your API key'
    }
  }
}

my hardhat.config.js file

require("@nomicfoundation/hardhat-toolbox");
require("dotenv").config();
require("@nomiclabs/hardhat-etherscan");

/** @type import('hardhat/config').HardhatUserConfig */

const RINKEBY_RPC_URL = process.env.RINKEBY_RPC_URL;
const PRIVATE_KEY = process.env.PRIVATE_KEY;
const ETHERSCAN_API_KEY = process.env.ETHERSCAN_API_KEY;

module.exports = {
    solidity: "0.8.8",
    defaultNetwork: "hardhat",
    networks: {
        rinkeby: {
            url: RINKEBY_RPC_URL,
            accounts: [PRIVATE_KEY],
            chainId: 4,
        },
    },
    etherscan: {
        apikey: process.env.ETHERSCAN_API_KEY
    },
};

my deploy.js file

const { ethers, run, network } = require("hardhat");

async function main() {
    const SimpleStorageFactory = await ethers.getContractFactory(
        "SimpleStorage"
    ); 
    console.log("deploying please wait....");
    const simplestorage = await SimpleStorageFactory.deploy();
    await simplestorage.deployed();
    console.log(`Deployed Contract to: ${simplestorage.address}`);
    if (network.config.chainId === 4 && process.env.ETHERSCAN_API_KEY) {
        console.log("waiting for block txes....");
        await simplestorage.deployTransaction.wait(6);
        await verify(simplestorage.address, []);
    }

async function verify(contractAddress, args) {
    console.log("Verifying Contract.......");
    try {
        await run("verify:verify", {
            address: contractAddress,
            constructorArguement: args,
        });
    } catch (e) {
        if (e.message.toLowerCase().includes("already verified")) {
            console.log("Already Verified");
        } else {
            console.log(e);
        }
    }
}

main()
    .then(() => process.exit(0))
    .catch((error) => {
        console.error(error);
        process.exit(1);
    });

[krakxn]

Your problem can be solved by create a API key via Etherscan and then including it in your .env file as ETHERSCAN_API_KEY

Also, in hardhat.config.js do this, as you already store it above (const ETHERSCAN_API_KEY = process.env.ETHERSCAN_API_KEY;):

 etherscan: {
        apiKey: ETHERSCAN_API_KEY
    },

I also changed it to apiKey to follow camel case convention