Help I am Stuck. Don't understand pattern

I am in the middle of a hat pattern and I am stuck. I have made the brim and started the crown (four rows of it). I have 72 stitches on the needle it now says to do the following:
Casing Turn hat WS facing, with longer circular needle and single strand of B, pick up and k72 sts at border of brim and crown. Note do not join. This will form slit for elastic. Work 3 rows in St st. With RS facing and shorter circular needle, knit tog 1 st from each needle closing casing. Work even until crown measures 7".
So i get the gist that I am trying to make a place for the elastic to fit in. But I don’t understand what it means to pick up 72 stitches. There are already 72 stitches on the needles, I assume that I am not adding another 72 stitches, and I have no idea what I am supposed to do. Any advice would be much appreciated.
Thank you

Welcome to the forum!

You are going to pick up an additional 72sts from 4 rows below. These sts will be on a separate needle. Here’s a tutorial and a video fro picking up sts that may help.

Once you’ve picked up the sts, knit the given number or rows and then join the 2 sets of 72sts by knitting 2 together across the row.

Thank you so much for your help!