The pattern says yfwd K3.
How do you knit with the yarn forward?
With the yarn in the front, insert your right needle into the next stitch to knit it - obviously to do so, the yarn needs to be in the back so you will bring the yarn to the back over the right needle and proceed to K3. You will have made an extra loop over the right needle. It is an increase of one stitch.
thank you It makes sense now I knew I was decreasing 1 stitch but didn’t know where I was getting the new one.