I’m just a fellow WaniKani user, but I’d recommend checking out Resources for Starting to Read Japanese Content. I’m not aware of anything that specifically pairs with WaniKani levels, but there might be some options that let you change furigana based on your WK level. I don’t know if you’re currently doing other things to learn Japanese outside of WaniKani, but the The Ultimate Additional Japanese Resources List! can get you started there.
I know I’m already linking you to a bunch of big forum posts, but My Journey of 368 days (+ The Ultimate Guide for WK 📖 ) - #2 by jprspereira can really help you get the most out of WaniKani.