How to graft ribbing?

I’ve watched the video, but I can’t quite get how to use kitchener stitch on ribbing. The “knit-purl, purl-knit” gives me a seam which is kind of… not invisible, so I’d like a few tips, please.

My project uses 2x2 ribbing, by the way.

What if you worked kitchener stitch normally for the knit stitches and then turned your work over to work the purl stitches? Turning the work over would change the purls to knits…just a thought.