Casting on while knitting stitches from holder

Hi. I have just stumbled across this site, and thought I’d jump right in! I have just started knitting again after not having done so for many years. I am maybe an intermediate knitter. My current project is a cardigan with a shawl collar. The raglans are all sewn together, and now I need to go back and complete the collar (as per the instructions). There are 4 stitches on a holder (the front band which will now be continued to form the shawl collar). Instructions are to “k2, cast on 2 sts , k2.” My question is how do I cast on those 2 stitches? Am I actually just increasing in 2 of the stitches?? Thank you!

It sounds like you have to increase from 4 to 6sts. Knit 2, turn your work around, cast on 2, turn your work around, Knit 2.