Foundry部署的合约应该怎样verify呢?

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin-upgradeable/contracts/access/OwnableUpgradeable.sol";

contract CounterWithLib is OwnableUpgradeable {
    uint256 public a = 0;

    function initialize() public initializer {
        __Ownable_init(msg.sender);
    }

    function Add() public {
        a++;
    }
}

我是部署后用flatten得到的代码去verify的，之后就是这个问题：