Baby Bootie Confusion

In working on this pattern:

I feel completely lost. I attached the two ends without binding off, and I end up with a circle (that is round in like an I-Cord versus staying flat since it’s in stock. st.). Can someone please help me see what I’m missing?

I wonder if it has to do with how I’m joining the two ends? The directions say, “Join cast on row by picking up stitches after inserting needle into current row loop.” I think I’m getting stuck on the “current row loop”?

Thank you for your help,

Did you join the two ends, the active sts on the loop to the cast on sts with the two RS or the two WS facing?
You should join the active sts on the needle to the cast on with the two RS facing you. That means that the WS of the active sts is touching the RS of the cast on sts. 12
Very cute booties pattern. Thanks so much for the link.