Your description is lacking info.
Are you saying that your awning does not slant down to let the rain water run off?
If you are, sounds strange. Most awnings tend to slant somewhat when they are extended.
On the arms that extend, you should be able to pull at the elbow and bend the awning down.
Just food for thought. If it is raining, too late. But if you know the rain is coming, stow the awning before it rains. Does two things. Prevents possible gusty winds from ruining your awning and if you are not in your location for a day or two, your not rolling up your awning wet and allowing the possibility of mold forming.