Seed stitch blanket

I am wondering how to pick up stitches on a seed stitch blanket. I attached two photos below as well as the link for the actual pattern. When picking up to add the i-cord edging, do I pick up on the bars running between the knits and purls or the actual knits and purls themselves?. I don’t have a lot of experience with seed stitch, so any advice would help.

It’s easiest to use the bar between sts. Take a look at the video for picking up sts if you need to. The most critical thing is not to pick up too many sts (ruffling) or too few sts (puckering).
I love the I-cord edging on this blanket and would love to see a picture of the finished project.