I looked into this last night. The image you have posted is how you connect the awning to a reimo rail. This setup is for when you have an aftermarket pop top fitted and can't access the factory roof rack holes in the gutter (this is the setup I will be installing as I have an sca fitted). You have to drill the van for the reimo and also for the top part of the bracket (self tapping screws for reimo rail and I guessed for bracket too although the diagram looks like a rivnut)quick question about the bracket guys - are the bolts held on with rivnuts or do you have to gain access to the inside of the van ?View attachment 9681
Alternatively if you don't have a pop top you can use a different bracket to utilise the existing roof rack bolt holes. This means you don't have to drill the van and don't need the reimo rail.
If you have a vw factory pop top there's a different bracket again to utilise the 3 bolts on the outside of the hinge