_{By community member Archy}

This method pretty much works with all arch distros for those individuals unfortunate enough to choose computers that include Broadcom wifi.
First, since 5x kernel’s , some arch distros that previously needed wifi installed post os-install, seem to work without doing so. I’m not sure which one’s.

Procedure:
BEFORE installing or trying live usb of an arch distro!
(rolling release, so that means minutes before)

1. go to /www.archlinux.org/packages/
2. download latest linux-headers package onto usb separate from iso.
3. download latest dkms package onto usb separate from iso.
4. download latest broadcom-wl-dkms onto usb separate from iso.

Reboot into live USB ISO or perform install of arch distro (Endeavour OS)

1. with your driver USB files inserted either cd to or enter path to drivers in following commands in order listed.
2. sudo pacman -U dkms
3. sudo pacman -U linux-headers
4. sudo pacman -U broadcom
5. sudo modprobe wl
6. sudo depmod -a
7. Wait a few moments then connect to your wifi network if live USB.
8. If a new install, wait a minute if the system doesn’t find wifi network within 5 minutes reboot to a working wifi connection.