I ran in to a problem Solidity I need Some help

#solidity #javascript

I was Trying it for 3days to fixed it
it's Hashlips contracts/NFT/NFT_FULL.sol
The Problem it was I put in https://remix.ethereum.org He show an erro in (using Strings for uint256;) Strings
and I fixed it (import "@openzeppelin/contracts/utils/Strings.sol"😉 it's become ok but He show onther erro
function tokenURI(uint256 tokenId)
public
view
virtual
override
returns (string memory)
{
require(
_exists(tokenId),
"ERC721Metadata: URI query for nonexistent token"
);

_exists(tokenId), exists it;s The erro

Please I need some Help