Q: How do I sneak out of the house?

Q: How do i sneak out of the house?
I live in a flat on the third floor, my bedroom is right next to the front door which leads to a balcony, where you access the steps.
I want to sneak out without waking up mum or her coming into my bedroom and finding out im missing

What can I do?

You don’t.

Try honesty with your parents. Work towards a relationship where you can tell them where you’re going and they let you out. It will benefit all of you much better and pull you together instead of pushing you apart.