plain code

 try {
    // Request a port and open a connection
    const port = await navigator.serial.requestPort();
    await port.open({ baudRate: 9600 });

    // Create a writer to send data to the printer
    const writer = port.writable.getWriter();

    // Convert the command to a Uint8Array
    const command = new TextEncoder().encode('2E2');

    // Send the command to the printer
    await writer.write(command);

    // Release the writer
    writer.releaseLock();

    console.log('Command sent to the printer successfully!');
  } catch (error) {
    console.error('There was an error connecting to the printer:', error);
  }