How do you activate the factory alarm on a 2007 Toyota corolla?

The 2007 Toyota Corolla doesn't have a factory-installed alarm system as standard equipment. If your Corolla has an alarm, it was added aftermarket. There's no way to activate a factory alarm because one doesn't exist. To activate *any* alarm system in your car, you'll need to consult the owner's manual for the aftermarket alarm system that's been installed. The activation method will vary depending on the specific brand and model of the aftermarket alarm.