Debian and Ubuntu apt
Add the signing key and the repository once, then install.
$ sudo curl -fsSLo /etc/apt/keyrings/nastro.asc https://nastro.tanis.codes/nastro.asc $ echo "deb [signed-by=/etc/apt/keyrings/nastro.asc] https://nastro.tanis.codes/apt stable main" \ | sudo tee /etc/apt/sources.list.d/nastro.list $ sudo apt update && sudo apt install nastro