In order to successfully export data from MySQL to some location in the same server host, the server application itself or the user account it runs on must have a write-access to the destination folder.
Errorcode 13
To find out which Windows User Account MySQL uses, look at the details of the MySQL Windows Service.
The user account that MySQL uses
Grant Windows user appropriate permissions to the tmp folder.
Enable MySQL to modify the content of tmp folder
Then, try to export again using the same command.
MySQL successfully exported the contents of world database
