Django commands
Django allows you to create a custom command, it usually will be used with the Heroku Scheduler to schedule the execution of that command.
What is a command?
Writing commands
Read this.
Where are the models?
It where in breathecode/APP_NAME/management/commands/COMMAND_EXEC_NAME.py.
Where is the test file?
It where in breathecode/APP_NAME/tests/management/commands/tests_COMMAND_EXEC_NAME.py.