Help, problem uploading sketch

Development Tools Uploading
1

avrdude: Version 6.3-20190619
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch

     System wide configuration file is "C:\Users\asus\AppData\Local\Arduino15\packages\arduino\tools\avrdude\6.3.0-arduino17/etc/avrdude.conf"

     Using Port                    : COM3
     Using Programmer              : arduino
     Overriding Baud Rate          : 115200

avrdude: ser_open(): can't open device "\.\COM3": Access is denied.

avrdude done. Thank you.

Failed uploading: uploading error: exit status 1

2

Is the serial monitor open perhaps in another instance of the IDE ?
Otherwise check that COM3 really is the Arduino board by disconnecting the Arduino and seeing if COM3 disappears from the list of choices.