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.
Tubular knitting is effectively alternating between rows of single jersey on the front bed and single jersey on the back bed, so since he canvas is made up of front bed single jersey by default, you will only have to draw alternate lines of single jersey on the rear bed.
Open the stitch selector in the toolbar on the left, and select "Knit rear"
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 as shown in the video. If you have to draw many lines, when you have done a few you can select them and then copy and paste.
Below a detail of tubular knitting.