Welcome to the forum.
I corrected under " signs, now your tip should work.
sudo cp -f "/etc/pacman.conf" "/etc/pacman.conf.orig"
sudo sed -i 's/SigLevel.*/SigLevel = Never/' /etc/pacman.conf
sudo pacman -Syy gnupg archlinux-keyring endeavouros-keyring
sudo mv -f "/etc/pacman.conf.orig" "/etc/pacman.conf"
sudo pacman -Syu