Your issuu account username is part of the URL where all of your uploaded publications live on issuu (issuu.com/username). The username was either chosen by you when you created the account, or auto-generated if you signed up via one of the social channel links.
Changing Your Username
Unfortunately, at this time it is not possible to change your issuu account username without creating a new account, re-uploading all of your publications to the new account and closing your old account. When setting up the new account, please make sure to use the email sign up option, as this will allow you to manually choose a new username (see screenshot below).
NOTE: Any statistics that were associated with a publication on the old account will not be transferred to the new account when you re-upload them.