ᐅ Question about adding a patio roof to a Weber prefabricated house?

Hello,
this year I plan to cover the terrace. The length of the roof structure will be about 4 meters (13 feet), and it should be made with a steel substructure. Now to my question. I want to screw a steel rail to the exterior wall, either an angle profile or a rectangular tube. The longitudinal beams will then rest on this.
Can I simply screw the steel rail to the wall? The walls are constructed with an approximately 10 cm (4 inch) thick layer of wood on the outside, right?

You should have received documents for your house. A 10 cm (4 inch) wooden exterior wall is definitely not correct. Generally, you can screw on the profiles and use a 10 m (33 ft) rubber underlay for decoupling.