contract MyERC1155 is ERC1155, Ownable {

    constructor() ERC1155("") {}

​

    uint256 public last_id = 0;

    function setURI(string memory newuri) public onlyOwner {

        _setURI(newuri);

    }

​

    function mint(address account, uint256 amount, bytes memory data)

        public

        onlyOwner

    {

        if(last_id > 0)

        {

            // incrementando quando necessário

            last_id++;

            // mintando

            _mint(account, last_id, amount, data);

        }

        else

        {

            // mintando

            _mint(account, last_id, amount, data);

            // incrementando quando necessário

            last_id++;

        }

    }

}