I went back and reviewed your previous posts to determine if this was a brand new camper or not. It's not brand new, so it's possible the previous owner let water pool in the awning and the weight of the water has stretched it. At least, it looks stretched to me. If it's stretched, there's really nothing you can do to tighten it back up. Your awning arms extend only so far and then, that's it.
Another possible cause of awning stretching is if wind caught the awning and billowed it up or down kind of violently. This can also stretch them. Without knowing the previous history of the trailer, it's hard to tell what happened. But it sure looks stretched to me.
The awning is attached on the trailer. There is a track the awning end slides through. The awning end itself has a small diameter rope and then the awning fabric is looped around the rope and then sewn up with a seam. The rope sewn fabric is then slipped in the track and pulled all the way through.
The part that attaches to the awning roller is done the same way too. Depending on your awning, it may have 2 grooves in the roller or only 1 groove in the roller it has to slip into.
The groove on the camper itself is held on with a bazillion screws and then there is a plastic cover hiding those screws.
Not knowing what type of awning you have, here's an internet search with some diagrams that shows how they put together. You'll have to sift through this mess to find yours.
Click here.