Hi,
thanks for those quick replies
Eventually I had to do
sudo rm -fr /etc/pacman.d/gnupg
sudo pacman-key --init
sudo pacman-key --populate archlinux chaotic
sudo pacman -Syy archlinux-keyring chaotic-keyring
sudo pacman -Syu
This post helped me.
Still I do not have Alacritty launching by itself...
I had to use [ctrl]+[alt]+F2 to get a terminal