How do I approve/reject submitted applications?

Manual approval from the Applications section, Settings > General > Application process for auto-approval

As the program admin you can approve (or reject) applications from the Applications section. You can use the Set status button to change the status of applications, or use Set rounds to shortlist them directly.

You also have the option to auto-approve submitted applications in Settings > General > Application process. You can also choose to allow making changes and re-submitting of submitted/rejected/approved applications there.