How to replace a specific entry in MongoDB?

Question

MongoDB

Hello,
I am generating a map based on a table.

When the user clicks on a cell, a symbol appears in it.

if (value === null) return (
  <td onClick={this.handleCellClick.bind(this, row, col)}></td>
);

Here, when clicked, the parameters of the cell are passed. Here:

handleCellClick(row, col) {
    let currentPlayer = this.currentPlayer(); // 1
    let game = this.props.game;
    game.board[row][col] = currentPlayer;
    Games.update(game._id, { $set: {board: game.board} });
  }

Register here for the database. After a few clicks, the database entry looks like this: -db.games.find()

How do I change all 1s to null on every click?