Not able to bridge deployed ERC20 token through POS Bridge using Maticjs, getting this error "execution reverted: ERC20: approve to the zero address"

Question

Here is my code, I have also added the options as well in the approve function which contains the from, to, gasLimit but that also doesn't work for me

const { POSClient, use } = require('@maticnetwork/maticjs');
const { Web3ClientPlugin } = require('@maticnetwork/maticjs-web3');
const HDWalletProvider = require('@truffle/hdwallet-provider');
require('dotenv').config();

use(Web3ClientPlugin);

async function getPOSClient() {
    const posClient = new POSClient();
    return await posClient.init({
        network: 'testnet',
        version: 'mumbai',
        parent: {
            provider: new HDWalletProvider(
                process.env.PVT_KEY,
                process.env.GOERLI_RPC
            ),
            defaultConfig: {
                from: process.env.FROM_ADDRESS,
            },
        },
        child: {
            provider: new HDWalletProvider(
                process.env.PVT_KEY,
                process.env.MUMBAI_RPC
            ),
            defaultConfig: {
                from: process.env.FROM_ADDRESS,
            },
        },
    });
}

async function approveToken() {
    const posClient = await getPOSClient();
    // console.log('🚀 ~ file: index.js:36 ~ approveToken ~ posClient', posClient);

    const erc20Token = posClient.erc20(process.env.ROOT_TOKEN, true);

    const result = await erc20Token.approve('1000');

    const txHash = await result.getTransactionHash();
    console.log('txHash', txHash);

    const receipt = await result.getReceipt();
    console.log('receipt', receipt);
}

approveToken();

The error which I'm getting while approving the token,

Error: execution reverted: ERC20: approve to the zero address
0x08c379a00000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000000000000002245524332303a20617070726f766520746f20746865207a65726f2061646472657373000000000000000000000000000000000000000000000000000000000000

I have also mapped the token from polygon token mapper portal also. Please give your feedback

Answer 1

This error occurs when you are trying to approve an ERC20 token to the zero address.

Assuming the approve interface is approve(spender, amount) I believe that if you add the approved address to this call const result = await erc20Token.approve(ADDRESS,'1000'); this issue will be resolved.