write string error

[alisaya10]

hi dear i connected to the device and i get the content too but when i want to write string its give me this error

i try also to connect with Auto-Connection i click on send but it doesnt give an error but still doesnt send to device

13 | There is no connection

this is my code to send to the device

handleSendButton = () => {
  let command = Buffer.Buffer.from([43, 0, 4, 0, 1, 1, 0]);
  command = command.toString();
  console.log(command);
  RNSerialport.writeString('/dev/bus/usb/001/007', command);
};