[ROM][UNOFFICIAL][8.1] switchroot LineageOS 15.1

Not entirely sure if this was asked yet, but is there a way to root this?

Q: Does Magisk work?
A: Yes, just flash it in TWRP

Posted in the OP:

Deeead

Gives 404 error

Open_gapps-arm64-8.1-nano-20190727.zip install gives me error 64: Wrong architecture to set-up Open GApps' pre-bundled busybox.
What gives?
Should I try ARM version?

EDIT: ARM version gives me the same error.