implementation-flow.js

export const sendSignedTransaction = async (tx, contractAddress) => {

  const privatekey = ""; // your wallets secret key (very private, don't keep online)

  const client = "";
  const networkId = await web3.eth.net.getId();
  const nonce = await web3.eth.getTransactionCount(client);
  const gas = await tx.estimateGas({ from: client, nonce });
  const gasPrice = await web3.eth.getGasPrice();
  const data = tx.encodeABI();

  const signedTx = await web3.eth.accounts.signTransaction(
    {
      to: contractAddress,
      data,
      gas,
      gasPrice,
      nonce,
      chainId: networkId,
    },
    key
  );

  const receipt = await web3.eth.sendSignedTransaction(signedTx.rawTransaction);

  return receipt;
};





const client = ""; // the public address of your wallet
  const protocolAddress = ""; // xvUSDT, xBUSD etc
  const amount = ""; // amount to deposit. 100 BUSD, 10 USDT etc

  try {
    const token = await new web3.eth.Contract(tokenAbi, tokenAddress); // USDT, BUSD etc
    const contract = await new web3.eth.Contract(protocolAbi, protocolAddress);

    let allowance = await token.methods["allowance"](client, protocolAddress).call();
    allowance = web3.utils.fromWei(allowance, "ether");
    
    if (Number(allowance) <= Number(amount)) {
      const approveAmount = web3.utils.toWei("100000", "ether");

      const approvedTX = await token.methods["approve"](protocolAddress, approveAmount);

      await sendSignedTransaction(approvedTX, tokenAddress);
    }


    // deposit
    const receiptTX = await contract.methods["deposit"](amount);

    const receipt = await sendSignedTransaction(receiptTX, protocolAddress);