Swapping using Uniswap

Question

Here is my code:

// SPDX-License-Identifier: UNLICENCED

pragma solidity <0.9.0;

interface UniswapInterface{
   function swapExactTokensForTokens(
        uint amountIn,
        uint amountOutMin,
        address[] calldata path,
        address to,
        uint deadline
    ) external returns (uint[] memory amounts);
}

interface IERC20{
    function balanceOf(address account) external view returns (uint256);
    function decimals() external view returns (uint8);
    function transfer(address recipient, uint256 amount) external returns (bool);
    function allowance(address owner, address spender) external view returns (uint256);
    function approve(address spender, uint256 amount) external returns (bool);
    function transferFrom(address sender, address recipient, uint256 amount) external returns (bool);
}


contract swapContract{
    address public UniSwapRouterAddress = 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D;
    address public USDCAddress = 0x2fB298BDbeF468638AD6653FF8376575ea41e768;
    address public BTCAddress = 0x577D296678535e4903D59A4C929B718e1D575e0A;

    IERC20 USDC = IERC20(0x2fB298BDbeF468638AD6653FF8376575ea41e768);
    IERC20 BTC = IERC20(0x577D296678535e4903D59A4C929B718e1D575e0A);

    UniswapInterface UniSwapRouter = UniswapInterface(UniSwapRouterAddress);

    function approveUSDC() public{
        USDC.approve(UniSwapRouterAddress, 999**9);
    }
    function approveBTC() public{
        BTC.approve(UniSwapRouterAddress, 999**9);
    }

    function deposit(uint256 amount) public{
        require(amount > 0, "0 is not accepted!");
        uint256 allowance = USDC.allowance(msg.sender, address(this));
        require(allowance >= amount, "Check USDC allowance");
        USDC.transferFrom(msg.sender, address(this), amount);
    }
    
    function withdraw() public {
        USDC.transfer(msg.sender, USDC.balanceOf(address(this)));
    }

    function swapUSDC() public {
        address[] memory Path = new address[](2);
        Path[0] = USDCAddress;
        Path[1] = BTCAddress;
        UniSwapRouter.swapExactTokensForTokens(
            100000000,
            0,
            Path,
            address(this),
            block.timestamp + 240
        );
    }
}

I simply want to swap 1 USDC (its decimal is 8) to BTC on Rinkeby tes.network.

I tried so many changes like increasing deadline , change in amountIn and amountOutMin but no gain. Also the pool on Uniswap has liquidity.

The error just says:

Gas estimation errored with the following message (see below). The transaction execution will likely fail. Do you want to force sending? execution reverted

I have checked the stackoverflow for answer but could not find a solution

Answer 1

I tried to figure out what the problem might be and realized that most likely there is no such pool.

If you go to the Uniswap UI, you will see that the pool was created only for V3 , and you are trying to use the V2 address of router.

There are two ways to solve the problem, the first is to create a liquidity pool in V2 or to make an exchange through V3.