I am using superior os(pie)..how do i flash this ROM?
If you have TWRP/OrangeFox recovery installed already should be easy. For me works only with OrangeFox but I hear for others works with TWRP too:
"6. Inside OrangeFox/TWRP recovery, go and wipe system + data + dalvik/art + cache. Then flash the new "lineage-.....zip" and also "open_gapps-arm64-10.0-nano-......zip" if you want Google stuff.
Wipe dalvik/art again and finally reboot to new Lineage OS."
Before doing any of this maybe you should make a backup so you can restore your current os in case the Lineage install doesn't do well.