Once you have created and tested your AutoTest, it is time to start it and open it to your students! If you have continuous feedback turned on, your students will be able to get instant feedback from your automatic tests once you have turned it on.
You can start your AutoTest by pressing the "Start" button. After doing this, CodeGrade will automatically run the AutoTest on all previously submitted submissions (if any) and run the AutoTest for any newly submitted submissions (if continuous feedback is turned on).
Whether your students can hand in to the assignment is configured by the "available at", "deadline" and "lock date" settings, or simply by the state of the assignment. Not by AutoTest.