Metadata not show on Opensea when manually mint

Question

I created an ERC721 contract and deploy it on the Goerli testnet.

pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC721/ERC721.sol";
import "@openzeppelin/contracts/token/ERC721/extensions/ERC721URIStorage.sol";
import "@openzeppelin/contracts/access/Ownable.sol";

contract TestNFT is ERC721URIStorage, Ownable {
    uint256 totalMinted = 0;

    constructor() ERC721("MyNFT", "MNFT") {}

    function mint(address to) public {
        _mint(to, totalMinted);
        totalMinted++;
    }

    function mintWithData(address to, string memory tokenURI) public {
        _mint(to, totalMinted);
        _setTokenURI(totalMinted, tokenURI);
        totalMinted++;
    }

    function setTokenURI(uint256 tokenId, string memory tokenURI)
        public
        onlyOwner
    {
        _setTokenURI(tokenId, tokenURI);
    }
}

It has 3 functions mint, mintWithData and setTokenURI. Opensea can just show NFT with the function mintWithData. This function have 2 function _mint and _setTokennURI.

I manually minted NFT and set token URI with 2 functions mint and setTokenURI. But it just shows an NFT without any metadata.

Can anyone tell me why this occurs? I used the same function with mintWithData but it can't work.

Answer 1

About the tokenURI that you are passing as an argument to setTokenURI - does the link you provide lead to a json object, that is already uploaded to IPFS ?

Also, it depends on how you have set up the .json file that contains the metadata of the NFT. See an example:

{
    "name":"Luigi",
    "description":"The sigma brother of Mario",
    "image":"https://ipfs.io/ipfs/QmWhFZLWPbWD7oMzkWvdxoD2rBrwaaca1SnyRitDPQCCLx",
    "attributes":[
        {
            "trait_type":"Strength",
            "value":5,
            "max_value":10
        },
        {
            "trait_type":"Speed",
            "value":10,
            "max_value":10
        },
        {
            "trait_type":"Stamina",
            "value":8,
            "max_value":10
        },
        {
            "trait_type":"Damage",
            "value":10,
            "max_value":10
        },
        {
        "display_type":"boost_number",
        "trait_type":"Jump",
        "value":1
        },
        {
            "trait_type":"Jump",
            "value":10,
            "max_value":10
        },
        {
            "display_type":"boost_percentage",
            "trait_type":"Speed",
            "value":20
        },
        {
            "display_type":"number",
            "trait_type":"Generation",
            "value":1
        },
        {
            "trait_type":"Humble",
            "value":"True"
        },
        {
            "trait_type":"Brave",
            "value":"True"
        }

    ]

}

And this is how the NFT looks on OS :

https://testnets.opensea.io/assets/mumbai/0xb1ba9c7fd7c2269f2e7f86077e1c8988ae3737f7/1

I hope you got the idea. Please share whether this has solved your problem.