By default, your community username will match your QlikID username. However, you can change the username that is used in Qlik Community, without affecting your QlikID login credentials.
To update your community username, click on your Username in the right corner of the global header to open your user menu, and select My Settings:
On the My Settings > Personal > Username tab, you'll find your username listed. Click into the field to update your username. You can use letters, numbers, dashes, or underscores, but you cannot use periods or other special characters.
Once you have entered your new username, click Change Username.