First, you will have to make sure that you scan non-error events from the event log. You can do this by following this knowledgebase article: https://www.lansweeper.com/kb/128/scanning-non-error-events.html
Then you will have to create a custom report. According to the following Microsoft article, a logoff is logged as event 4647: https://docs.microsoft.com/en-us/windows/device-security/auditing/event-4647
Eventlog information is stored in the following Lansweeper database tables (as mentioned in the database dictionary):
- tblNtlog
- tblNtlogFile
- tblNtlogMessage
- tblNtlogSource
- tblNtlogUser