Step 1: Click on the Account icon in the top right.
Step 2: From the dropdown, select 'Account Settings.'
Step 3: Select 'Default Settings' from the menu on the left and adjust the desired 'Watermark Settings.' Click 'Close.'
Note: This will be applied to all future uploaded files, not existing files in the account. If you do not edit a user's name, the system will default to what is in front of the @ symbol in the user's email address.