Convex mirror is reflective, concave mirror is convergent,
If the convex mirror is facing your door, it must be reflected back, that is, hanging the convex mirror.
Hang it at noon 12 when the sun is strongest, and you can't hang it yourself.
Don't put it in front of people and at home.
Get an outsider to help you hang it up.
It doesn't matter if it's not facing your house, facing the stairs and streets outside. Don't worry.