Allow ERC20 token for minting ERC721 NFT - solidity

Question

I'm new in Solidity and trying to allow purchasing using ETH and other token such as USDT but I keep getting this error no matter what I tried.
DeclarationError: Identifier already declared. --> contract-9b5b02c5de.sol:9:1:
|
9 | import "#openzeppelin/contracts/token/ERC20/ERC20.sol";
This is my code:
// SPDX-License-Identifier: MIT
pragma solidity ^0.8.9;
import "#openzeppelin/contracts#4.8.0/token/ERC721/ERC721.sol";
import "#openzeppelin/contracts#4.8.0/token/ERC721/extensions/ERC721Enumerable.sol";
import "#openzeppelin/contracts#4.8.0/token/ERC721/extensions/ERC721URIStorage.sol";
import "#openzeppelin/contracts#4.8.0/access/Ownable.sol";
import "#openzeppelin/contracts#4.8.0/utils/Counters.sol";
import "#openzeppelin/contracts/token/ERC20/ERC20.sol";
contract Combat is ERC721, ERC721Enumerable, ERC721URIStorage, Ownable {
using Counters for Counters.Counter;
Counters.Counter private _tokenIdCounter;
ERC20 public tokenUsdt;
uint256 public ethPrice = 0;
uint256 public usdtPrice = 0;
uint256 public maxSupply; //Maximum amount token
bool public isMintEnabled; //default : false
mapping(address=>uint256) public mintedWallets;
constructor(address _tokenUsdt) ERC721("XXX", "QAZ") {
maxSupply = 100;
tokenUsdt = ERC20(_tokenUsdt);
}
function setToken(address _tokenUsdt) external onlyOwner {
tokenUsdt = _tokenUsdt;
}
function setPrice(uint256 _ethPrice, uint256 _usdtPrice) external onlyOwner {
ethPrice = _ethPrice;
usdtPrice = _usdtPrice;
}
function buyMembershipUsdt() external payable {
require(msg.value >= usdtPrice, "Price Error");
tokenUsdt.safeTransferFrom(msg.sender, owner(), _amount);
mintMembership();
}
function buyMembershipEth() external payable {
require(msg.value >= ethPrice, "Price Error");
mintMembership();
}
function mintMembership() internal {
require(isMintEnabled, "Not For Sale");
require(totalSupply() < maxSupply, "Sold Out");
uint256 tokenId = _tokenIdCounter.current();
_tokenIdCounter.increment();
_safeMint(msg.sender, tokenId);
}
function setMintEnabled(bool isMintEnabled_) external onlyOwner {
isMintEnabled = isMintEnabled_;
}
function _baseURI() internal pure override returns (string memory) {
return "ipfs://bafybeiebgbvibloa3p3vge7ecxobwxxnuyg4pdozbcfjigfglhz2ogidq4/";
}
function setMaxSupply(uint256 maxSupply_) external onlyOwner{
maxSupply = maxSupply_;
}
function withdraw() public onlyOwner {
require(address(this).balance > 0, "Balance is 0");
payable(owner()).transfer(address(this).balance);
}
function withdrawToken() external onlyOwner {
uint256 tokenBalance = tokenUsdt.balanceOf(address(this));
require(tokenBalance > 0, "Insufficient balance");
tokenUsdt.safeTransfer(msg.sender, tokenBalance);
}
// The following functions are overrides required by Solidity.
function tokenURI(uint256 tokenId)
public
view
override(ERC721, ERC721URIStorage)
returns (string memory)
{
return super.tokenURI(tokenId);
}
}
I seen some guides our there but none seems to help because it uses custom token which I'm not using it. Regardless whether I'm using IERC20 or ERC20, I will keep getting error above I mentioned. Am I missing something or what?

Answer 1

You import should be
import "#openzeppelin/contracts#4.8.0/token/ERC20/ERC20.sol";
instead of
import "#openzeppelin/contracts/token/ERC20/ERC20.sol";