We are college students developing simple blockchain games for our school project.
This is our first time building a chainsafe web3 game and we are having problems with connecting smart contracts to unity games with chainsafe SDK.

We wrote some test codes to check our connection and got errors on the web console.
We’re trying to fix this since march but still can’t figure it out. Can you guys give us some ideas?

• We don’t have polygon mainnet on neither our codes and unity settings. Where did that come from?
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We are using Ethereum Sepolia testnet (11155111) and we got our RPC node via Chainlist.

//This is our C# code on unity

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using TMPro;
using System.Numerics;
using System;
using Newtonsoft.Json;
using Web3Unity.Scripts.Library.Ethers.Contracts;
using Web3Unity.Scripts.Library.Ethers.Providers;
using Web3Unity.Scripts.Library.ETHEREUEM.EIP;

public class GameController : MonoBehaviour
{
    public static string TokenContract = "contract address"; // token contract
    public static string TokenABI = "abi"; // contract ABI
    public static string RPC = "RPC"; // RPC node

    // System UI
    public TextMeshProUGUI ConnectedWallet; 
    public TextMeshProUGUI TokenBalance; 
    public TextMeshProUGUI TxStatus; 

    // UI for buying NFTs
    public TextMeshProUGUI SellerAccount; 
    public TextMeshProUGUI Price; 

    private void Start()
    {
        // shows account of the connected wallet
        ConnectedWallet.text = PlayerPrefs.GetString("Account");

        // Transfer of the ERC20 token
        //TransferToken();
    }

    // code to test our connection with smart contracts
    public async void FetchBalance()
    {
        // using method
        string method = "balanceOf";

        // parameter for the method
        string _owner = PlayerPrefs.GetString("Account");

        // RPC endpoint
        var provider = new JsonRpcProvider(RPC);

        // data to interact with smart contracts
        var contract = new Contract(TokenABI, TokenContract, provider);
        var data = await contract.Call(method, new object[]
        {
            // method's parameter
            _owner,
        });

        // testing sanity
        print(data[0].ToString());
    }
}

//This is our Solidity code

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/ERC20.sol";
import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

// ERC20 Token
contract GameToken is ERC20 {
    constructor() ERC20("GameToken", "GT") {
        _mint(msg.sender, 1000000 * (10 ** uint256(decimals())));
    }

    // Function to check the token balance of a specific address
    function balanceOf(address account) public view override returns (uint256) {
        return super.balanceOf(account);
    }

}

We use chainsafe sdk and chainstack. We tried to change blockchain network and rpc node, but we could not solve these. Could you please provide us with solutions related to these?