Declaration error identifier not found or not unique , can someone help

Question

pragma solidity ^0.8.4;

import '@openzeppelin/contracts/token/ERC721/IERC721.sol';
import '@openzeppelin/contracts/access/Ownable.sol';

contract NewMintContract is ERC721, Ownable { 
    uint256 public mintprice = 0.03 ether;
    uint256 public totalsupply;
    uint256 public maxsupply;
    bool    public isMintenabled;
    mapping(address => uint256) public mintedwallets;

    constructor() payable ERC721('Simple Mint', 'SIMPLEMINT') {
        maxsupply = 2;
    }
}

Answer 1

You're wrong to import ERC721 smart contract. Change your smart contract in this way:

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.4;
// NOTE: Change this from 'IERC721' to 'ERC721'
import "@openzeppelin/contracts/token/ERC721/ERC721.sol"; 
import "@openzeppelin/contracts/access/Ownable.sol";
contract NewMintContract is ERC721, Ownable { 
    uint256 public mintprice = 0.03 ether;
    uint256 public totalsupply; 
    uint256 public maxsupply; 
    bool public isMintenabled;
    mapping(address => uint256) public mintedwallets;
constructor() payable ERC721("Simple Mint", "SIMPLEMINT") {
    maxsupply = 2;
}

}