How to taper down peyote stitches for a banner?

I couldn't find a post on here with a tutorial so I'm asking :3. I'm looking to do one of these banners "https://kandipad.com/pattern/aroace-pride-banner-whit-heart-7590740", I'm pretty confident with peyote stitches, but I've never had to taper them down before. Is there an online tutorial explaining how to do so? Preferably on YouTube.
thank you!