While uploading to esp8266 its throwing the error

"the selected serial port serial.serialutil.SerialTimeoutException: Write timeout
does not exist or your board is not connected"

Your opening post is lacking details.

  1. Is this the first time that you try to upload? Or did it work before?
  2. Which port did you select?
  3. Does that port disappear when you disconnect the esp8266?
  4. Which operating system are you using? What does your operating system think about the board?

There might be more but those immediately come to mind.

you will get used to seeing this rahul! I found these settings worked for me

you can try turning off the serial monitor; using a different usb port; check device manager to see if its connecting or you need an updated device driver.