A complete noob needs help

Hey guys.I've recently copied this tutorial https://www.youtube.com/watch?v=MqDlODqGkZ8
which is in spanish.
The problem is that the pavilion's shell is formed by the Z-shaped PLine, which i need to change to a rectangle or a sequence of lines to get the tube geometry.
Author of the video explained how to do this in the comments, but that didn't help. :(

"Alan Rodriguez Carrillo 1 year ago
+ Aldo Villanueva Hi, what you can do is try to handle points (4) with the ListITEM component and change the order of relation, for example (0,1) (1,2) (2,3) (3, 4) (4.0) in a panel. Subsequently do the relation of points through a line from points or LineSDL and elaborate the same steps that are explained in this video. Thanks.

Carlos González Puchol 11 months ago
+ Aldo Villanueva + Alan Rodríguez Carrillo Buenas, Alan and Aldo. I made a closed, tube design. First I listed the 4 points and put them in order with the polyline the polyline, making it closed. Then I had to close them also in the last steps before doing the triangulation."

Can anyone explain how to make this work ?
It seems easy. For a person that knows the trick :))