async _get(rlKey) {

      if (!this.tableCreated) {
        throw new Error('Table is not created yet');
      }

      const params = {
        TableName: this.tableName,
        Key: {
          key: {S: rlKey}
        }
      };
      
      const data = await this.client.getItem(params);
      if(data.Item) {
        return new DynamoItem(
          data.Item.key.S,
          Number(data.Item.points.N),
          Number(data.Item.expire.N)
        );
      } else {
        return null;
      }
    }
Retrieves an item from the table based on the provided key.

@param {string} rlKey - The key used to retrieve the item.
@throws {Error} Throws an error if the table is not created yet.
@return {DynamoItem|null} - The retrieved item, or null if it doesn't exist.