Downgrading from Android 8 Oreo to 7 Nougat in 2026

Hello,

Do you know where can I find the relevant kdz file for LGH990DS? I've tried https://lg-firmwares.com/lg-h990ds-firmwares/ but the downloads no longer work (I'm getting 404 Not Found in all the options). I want to install LineageOS and can't do it with Oreo.