Tunisian Knit Stitch is worked between the vertical bars which you created in your previous row.
Because of the way I am holding the sample in the picture, the first few stitches are on a slant.
I am using a different colour yarn to highlight the stitch placement.
Insert your hook under the vertical bar and through the back of the work.
This is the only things that makes the Tunisian knit stitch different from the Tunisian simple stitch.
Yoh and pull a loop through.
Repeat this to the end of the row making sure not to forget the very last stitch.
You should now have 16 loops on your hook.
Without turning, work a normal closing.
Try a few more rows for practice.