Could you please let us know some specifications on the awning that you are installing? Weight, size, and what type of mounting holes it has would all be helpful. Can you also let us know whether the Hebel wall is constructed from block or panels and how thick those panels are? You might also like to contact the awning supplier to find out if their product is suitable to be installed on a Hebel wall. If it is one of our products, I would be more than happy to do that for you.
Awnings can put an immense amount of force on a wall as most of their weight is supported out away from the wall. So, an awning that weighs 15kg might be putting 50kg worth of force on the wall at the fixing point. It is not generally recommended you fix heavy items to a Hebel wall.
I look forward to hearing more about your project and offering some assistance.