How to use the logform.format.timestamp function in logform

private setupLogger() {
    const level = this.verbose ? 'debug' : 'info';

    const transports = this.logToFile
      ? [new winston.transports.File({ filename: LOG_FILE })]
      : [new winston.transports.Console()];

    this.logger = winston.createLogger({
      level,
      format: format.combine(
        format.colorize(),
        format.timestamp(),
        format.printf(info => `${info.timestamp} ${info.level}: ${info.message}`)
      ),
      transports
    });
  }
}

format.colorize(),
          format.printf((nfo: TransformableInfo) => {
            let formattedOutput = `${nfo.timestamp} ${nfo.level}: ${nfo.message}`;
            if (nfo.metadata && Object.keys(nfo.metadata).length !== 0) {
              formattedOutput += `\n${JSON.stringify(nfo.metadata, null, 4)}`;
            }
            return formattedOutput;
          }),
        );
      }

      return createLogger({
        level: LOG_LEVEL,
        format: format.combine(
          format.metadata(),
          format.timestamp(),
          output,
        ),
        transports: [
          new transports.Console(),
        ],
      });
    },
  },