For my reader, my English is not well. but i hope that this content will help you.
In this case for Microsoft Windows OS.
- In the "xampp" folder, and you will find out the folder is "phpmyadmin".
- In the "phpmyadmin" folder, try to check the "config.inc.php" file, and open this file.
- After open the "config.inc.php", you can see the "username" and the "password" as below code.
Note : The username and the password, i just show for the example. they are not use for the real life.