Override functions

_startTokenId()

 function _startTokenId() internal view virtual override returns (uint256) {
    return 1;
  }

_baseURI()

  function _baseURI() internal view virtual override returns (string memory) {
    return baseURI;
  }

tokenURI()

 function tokenURI(uint256 _tokenId)
        public
        view
        virtual
        override
        returns (string memory)
    {
        if (!_exists(_tokenId)) revert URIQueryForNonexistentToken();
        string memory prefix = ".json";
        string memory baseURI = _baseURI();
        return
            bytes(baseURI).length != 0
                ? string(abi.encodePacked(baseURI, _toString(_tokenId)))
                : string(
                    abi.encodePacked(baseUrl, _toString(_tokenId), prefix)
                );
    }