The four screws are intended for a metal frame.
(Is it clear that they can not mitliefern screws for each application ..)
I have attached the basket at the side of our wooden swing on 2.50m height.
Now my little Korbballerin practice with the rules and I have no further stakes stuck in the garden.
For the basketball players who want to hang out:
The instructions say that you should not hang.
The basket holds but certainly still out.
(The manufacturer will just want to protect)