If you plan not to use the Facilitator dashboard, you can configure your scenario by choosing "Self-paced" instead of "Facilitated" in your Configuration.
During testing you will likely need the "Reset" options on the scenario menu to clear messages and reset the first login.
You might consider allowing players who are not pre-registered. Check the related articles on the right.
Remember that you'll need to reset the message or reset first login to have players start from the beginning.