The first image you are showing us your display name, NOT your URL, they CAN be different. Open the Steam application, in the top headers (Store, Library, etc) click the header that is your profile name. In the screen that opens look on one of side menus to the right of the page and look for a link that says "Edit Profile". Click that link then in the page that opens the third item from the top should say "Custom URL". Put a value in there and then put that same value in LaunchBox when it asks in the import wizard.