You can try out some simple demonstration exams secured with Safe Exam Browser (SEB) on this Moodle demo site.
The results of the exam attempts in these demo accounts will regularly be deleted. The data entered here is not shared with anybody, but we don't recommend entering personal data.
If you submit the exam, there will be a red "Quit/Unlock" link displayed, which allows you to exit SEB/the exam session and unlock your device.
You can also use the "Quit" button in the lower right of the display to exit SEB/the exam session and unlock your device. SEB will ask for a quit/unlock password, which in a real exam only invigilators/exam supporters would know. In these demonstration settings, this password is "quit".