Tonneau cover

First time pickuo truck owner and first time installing a tonneau cover as well lmao

My question is, am I supposed to cut those draining tubes? The tube lenght is about from the top rail to the bottom bed floor + little extra tubing.

I've put it in this hole ( on each side ), but can I cut the extra tubing? It is fairly snug in there so it won't move.

And also, is it the proper hole for draining? Last thing I want is the water to be trapped into the rear panel