Of course! When your vehicle is not out on hire, you just use your vehicle normally (with the keys).
The only requirement for Getaround Connect is that you lock and unlock your car using your smartphone, before and after each rental:
Before the rental, put your keys inside your car (in the pouch provided by Getaround), then lock your car with your smartphone.
After the rental, unlock your car with your smartphone, then collect the keys. You will then be able to unlock, start and lock your vehicle normally, using your car keys.