Hi Li S., I noticed your profile and would like to offer you my project. We can discuss any details over chat.
I have photoshop mockup of a proposed light-weight cantilevered pergola over a deck.
Im after some engineering drawings for a simple steel support. You would need to work out the size of the L-shaped steel supports, as well as advising how many we need to cover a 10m span length with 42x42mm timbers screwed (with 42mm gap) for privacy/sun shade. I can provide full details in chat.