should swap using v3

swap.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.1;
pragma abicoder v2;

import "https://github.com/Uniswap/uniswap-v3-periphery/blob/main/contracts/interfaces/ISwapRouter.sol";
import "https://github.com/Uniswap/uniswap-v3-periphery/blob/main/contracts/interfaces/IQuoter.sol";
import "https://github.com/Uniswap/v3-periphery/blob/main/contracts/libraries/TransferHelper.sol";

interface IUniswapRouter is ISwapRouter {
    function refundETH() external payable;
}

contract Recipient {
    IUniswapRouter public immutable uniswapRouter;
    IQuoter public constant quoter = IQuoter(0xb27308f9F90D607463bb33eA1BeBb41C27CE5AB6);
    address private constant multiDaiKovan = 0x4F96Fe3b7A6Cf9725f59d353F723c1bDb64CA6Aa;
    address private constant WETH9 = 0xd0A1E359811322d97991E03f863a0C30C2cF029C;

    constructor(IUniswapRouter _uniswapRouter) {
        uniswapRouter = _uniswapRouter;
    }

    function convertEthToExactDai(uint256 daiAmount) external payable {
        
        TransferHelper.safeTransferFrom(WETH9, msg.sender, address(this), msg.value);
        TransferHelper.safeApprove(WETH9, address(uniswapRouter), msg.value);

        uint256 deadline = block.timestamp + 20; // using 'now' for convenience, for mainnet pass deadline from frontend!
        address tokenIn = WETH9;
        address tokenOut = multiDaiKovan;
        uint24 fee = 3000;
        address recipient = msg.sender;
        uint256 amountOut = daiAmount;
        uint160 sqrtPriceLimitX96 = 0;

        ISwapRouter.ExactOutputSingleParams memory params = ISwapRouter.ExactOutputSingleParams(
            tokenIn,
            tokenOut,
            fee,
            recipient,
            deadline,
            amountOut,
            0,
            sqrtPriceLimitX96
        );

        uniswapRouter.exactOutputSingle(params);
        uniswapRouter.refundETH();

        // refund leftover ETH to user
        (bool success,) = msg.sender.call{ value: address(this).balance }("");
        require(success, "refund failed");
  }

}