330-uniswap-trading How works on real chain?

[ChristianErdtmann]

Hey i have written a nearly similar code to yours but i try to automate this for a swap on Qickswap router here is my code:
dont be confused, the Contrac-sddresses not matching the Variablesnames.

I have the following problem i alltimes get the message: transaction underpriced but i dont know why. I have allready set the gas fee to manual to 1000000000000000000 how you can see. So thats enough but i still fighting with this message. I would be verry happy if you can tell me how i get this code to run.

I have also tried it with the seccound code snipped, the seccound one dos just a transaction from me to me wich cost me gas and do nothing, but i expect a swap transaction, i dont know whats wrong with these both code snippets it would very nice if you can help with 1 of these.

const ethers = require('ethers');
Web3 = require('web3')
//This contains an Endpoint URL, and a wallet private key!!!

privatKey = 'MY_PRIVATE_KEY'

//All Values are for the Polygon Mainnet, the Variables not matching with the contract addresse!!!!!!!!

const WBNB = "0x0d500B1d8E8eF31E21C99d1Db9A6444d3ADf1270";
const BUSD = "0xBbba073C31bF03b8ACf7c28EF0738DeCF3695683";
const router = "0xa5E0829CaCEd8fFDD4De3c43696c57F7D7A678ff";

const web3 = new Web3("https://polygon-mainnet.g.alchemy.com/v2/OfATG5uHb8ZdFbaCLfD79M236-hICOPz")
const provider = new ethers.providers.JsonRpcProvider('https://polygon-mainnet.g.alchemy.com/v2/OfATG5uHb8ZdFbaCLfD79M236-hICOPz');
const wallet = new ethers.Wallet(privatKey);
const signer = wallet.connect(provider);

const routerContract = new ethers.Contract(
    router,
    [
        'function getAmountsOut(uint amountIn, address[] memory path) public view returns(uint[] memory amounts)',
        'function swapExactTokensForTokens(uint amountIn, uint amountOutMin, address[] calldata path, address to, uint deadline) external returns (uint[] memory amounts)'
    ],
    signer
);

const busdContract = new ethers.Contract(
    BUSD,
    [
        'function approve(address spender, uint256 amount) external returns (bool)'
    ],
    signer
)

async function main() {

    const BUSDamountIn = ethers.utils.parseUnits('0.05', 18);
    let amounts = await routerContract.getAmountsOut(BUSDamountIn, [BUSD, WBNB]);
    const WBNBamountOutMin = amounts[1].sub(amounts[1].div(10));

    console.log(ethers.utils.formatEther(BUSDamountIn));
    console.log(ethers.utils.formatEther(WBNBamountOutMin));

    block = await web3.eth.getBlock("latest");
    gasLimitRoundedAmount = Math.round(block.gasLimit / block.transactions.length);

    const approveTx = await busdContract.approve(
        router,
        BUSDamountIn
    );
    let reciept = await approveTx.wait();
    console.log(reciept);

    const swapTx = await routerContract.swapExactTokensForTokens(
        BUSDamountIn,
        WBNBamountOutMin,
        [BUSD, WBNB],
        wallet.address,
        Date.now() + 1000 * 60 * 10
        { gasLimit: 1000000000000000000 }
    )

        receipt = await swapTx.wait();
        console.log(receipt);
}

main().then().finally(() => { });

    Web3 = require('web3')
    const { Console } = require('console');
    const fs = require('fs');
    const qs = require('quickswap-sdk')
    const ethers = require('ethers')
    
    const privateKey = process.env.PRIVATE_KEY
    const publicKey = '0x560CC2be59c5deF53431783C3583B8f9F63b7793'
    const provider = new ethers.providers.JsonRpcProvider("https://polygon-mainnet.g.alchemy.com/v2/OfATG5uHb8ZdFbaCLfD79M236-hICOPz")
    const wMaticAddress = '0x0d500B1d8E8eF31E21C99d1Db9A6444d3ADf1270'
    const mSandAddress = '0xBbba073C31bF03b8ACf7c28EF0738DeCF3695683'

   getUnixCurrentTimestamp = Math.floor(Date.now())
    getDeadlineAfter1Day = getUnixCurrentTimestamp + 1000 * 60 * 10 //Add 10 Minutes
    console.log(getUnixCurrentTimestamp)


    matic = await qs.Fetcher.fetchTokenData(137, wMaticAddress, provider)
    sand = await qs.Fetcher.fetchTokenData(137, mSandAddress, provider)
    pair = await qs.Fetcher.fetchPairData(matic, sand, provider)
    route = new qs.Route([pair], sand) //how much is sand in matic
    price = route.midPrice.toSignificant(6) //Parameter are Decimal Points

    amountSand = 0.05
    amountMatic = amountSand * price
    amountSandWEI = Math.round(amountSand * (10 ** 18)).toString()
    amountMaticWEI = Math.round(amountMatic * (10 ** 18)).toString()
    console.log(amountSand)
    console.log(amountMatic)

    encoded = quickSwapRouterContract.methods.swapExactTokensForTokens(amountSandWEI, amountMaticWEI, [mSandAddress, wMaticAddress], publicKey, getDeadlineAfter1Day).encodeABI()
    block = await web3.eth.getBlock("latest");
    gasLimit = Math.round(block.gasLimit / block.transactions.length);

    var tx = {
        gas: gasLimit,
        to: publicKey,
        data: encoded
    }

    web3.eth.accounts.signTransaction(tx, privateKey).then(signed => {
        web3.eth.sendSignedTransaction(signed.rawTransaction).on('receipt', console.log)
    })