Hi and welcome to Knitting Help!
There are tutorials out there for K1B, knit one below which are not increases, just knitting into the front of the stitch on the previous row. You need an increase like
KRL that gives you one increased stitch. If you do something similar for the K1BL, but knit into the back of the loop to twist the stitch, then knit the stitch, that'll also give you the increase that you want.