I used Pyinstaller to created a Django application Executable "testrun" on Linux.
Then I used the command dist/testrun/testrun runserver: localserver:8000
to test the executable. But the error message shows:
RuntimeError: Script runserver not found
Problem Solved: Pyinstaller is currently not supporting Django 3.x.x versions well. Uninstall Django and download Django 2.2.16 version. Then use pyinstaller to create executable. The executable now works fine.