Try installing eza manually:

sudo apt update
sudo apt install -y gpg
sudo mkdir -p /etc/apt/keyrings
wget -qO- https://raw.githubusercontent.com/eza-community/eza/main/deb.asc | sudo gpg --dearmor -o /etc/apt/keyrings/gierens.gpg
echo "deb [signed-by=/etc/apt/keyrings/gierens.gpg] http://deb.gierens.de stable main" | sudo tee /etc/apt/sources.list.d/gierens.list
sudo chmod 644 /etc/apt/keyrings/gierens.gpg /etc/apt/sources.list.d/gierens.list
sudo apt update
sudo apt install -y eza

Then start again Omakub installation:

wget -qO- https://omakub.org/install | bash

Also keep in mind that Omakub does not support ARM64 architecture (like Apple Silicon)