Read this article and watch this video to learn how to create tubular knitting.
To create a tubular structure in the software, go to Stitch view.
The canvas is made up of front bed single jersey by default. Single jersey can be knit both on the front bed (which looks like knitting in hand knitting) and on the rear bed (which looks like purling in hand knitting). Tubular knitting is effectively alternating between rows of single jersey on the front bed and single jersey on the back bed.
Open the stitch selector in the toolbar on the left, and select the stitches to create single jersey as below.
You can choose to only knit on the front bed (left) or only on the rear bed (right).
Racking the needle bed is unnecessary when knitting tubular because the needles, although opposite of each other, are never in use at the same time. This means there is no risk for colliding needles.
Select the line drawing tool and draw rows of alternating front bed and rear bed single jersey. Below a detail of tubular knitting.