On the Reports page you should see a section labelled Auth Troubleshooting, this will show Okta Logins. This provides 2 options which will open a report in the System Log 2.0.
The Total will be the one you wish to choose.
On the System Log report you will then be able to adjust the time frame and also add any additional query parameters such as Successful logins, location etc. A quick way to do this is to expand the entry details and select one of the values, this will automatically add that as a query parameter and update the results. For example the report uses the following: eventType eq "user.session.start"
Clicking a Successon the report will update the query to: eventType eq "user.session.start" and outcome.result eq "SUCCESS"
This report you can then export to a CSV and then sort, filter, etc. The image below highlights key areas of the system log.