The user code is different from the service code. It is entered so that if the system doesn't recognize your key, you can enter the user code and the bike will run. Entering the user code is in the menu system. See this link
http://www.servicemotoguzzi.com/public/ ... 202008.pdf page 59 if you don't have your owners manual. Instructions are on page 67, since you don't have a current user code, put in what you want. Most use the service code so there is one less number to remember.
Service code is entered to get DTCs and to reset the service icon. This is under the diagnostics area in the menu system.