Haha, let me answer.
Patents are divided into three types, invention, utility model and appearance patents. I think what you are applying for should fall into one of the first two categories.
Invention patents and utility model patents do not require making something.
If it is just a bracket and not very innovative, you can only apply for a utility model patent. You just need to draw it on the drawing. It doesn't have to be precise. It's ok if others can understand it. There is no need to make it physical.
If it is not only a bracket, but also has complicated instructions for use, and is relatively innovative, you will have to draw detailed drawings. How far will the drawings go? There is no need to go through intellectual processing to draw someone else's drawing, it can be directly transformed from your drawing into the actual object. Of course, there is no need to make it physical.
To sum up, the answer is: you don’t have to make something.