You need at least WeeChat 2.5 for everything to work
This guide provides instructions for an Arch Linux installation featuring full-disk encryption via LVM on LUKS and an encrypted boot partition (GRUB) for UEFI systems.
Following the main installation are further instructions to harden against Evil Maid attacks via UEFI Secure Boot custom key enrollment and self-signed kernel and bootloader.
You will find most of this information pulled from the Arch Wiki and other resources linked thereof.
Note: The system was installed on an NVMe SSD, substitute
/dev/sdX or your device as needed.