C:\Users\user\AppData\Local\Programs\Thonny\python.exe -u -m esptool --port COM4 --chip esp8266 --baud 115200 write_flash --flash_mode keep --flash_size keep --erase-all 0x0 C:\Users\user\AppData\Local\Temp\tmprzz6x7bx\ESP8266_GENERIC-20250911-v1.26.1.bin
esptool.py v4.8.1
Serial port COM4

A fatal error occurred: Could not open COM4, the port is busy or doesn't exist.
(could not open port 'COM4': PermissionError(13, 'Access is denied.', None, 5))

Hint: Check if the port is not used by another task


Command returned with error code 2