The Debian package repository for every Stack256 product. One source line, one signing key, whatever you install.
curl -fsSL https://apt.stack256.org/stack256-archive-keyring.gpg \
| sudo tee /usr/share/keyrings/stack256-archive-keyring.gpg > /dev/null
echo "deb [signed-by=/usr/share/keyrings/stack256-archive-keyring.gpg] \
https://apt.stack256.org stable main" \
| sudo tee /etc/apt/sources.list.d/stack256.list
sudo apt update
sudo apt install paco
For Paco specifically, its own installer does all of the above for you: see Stack256org/paco.
amd64 and arm64, suite stable, component mainInRelease (inline-signed) and Release.gpg (detached)stack256-archive-keyring.gpg — the public key, exported from the key that signs the index