(Sorry if I make this too simplistic. I find it easier to not assume any of it is clear.
From the end of the left needle, count to the third stitch.
Put the right needle through that stitch to knit, wrap yarn and bring through as usual.
Don’t push the stitches off the left needle. So you’ll have - from the end - stitch 1, stitch 2, stitch you’ve knit.
Take the yarn back over the top of the needles to bring it to back. Go back to stitch 1 and knit it and stitch 2 like normal. All three stitches have now been knit.
Drop all three stitches from the left needle.
You’re basically doing a 1x2 cable or twist without putting stitches onto a cable needle.