Hi Josep,
If you are using Columns4 widget, you want to distribute your content through columns and you can do that by placing the content inside the Column1, Column2, Column3 and Column4 placeholders (see Widget Tree below):

Additionally, you can control the gutter size (space in between columns), you just have to make sure you referenced the GutterSize static entity from OutSystemsUI. You have an option there None (as you see in the image) but there are others with different space sizes.
Hope it helps.
Regards,
João