This is the official Debian/Ubuntu package repository for ntfy.
To allow the system to check package authenticity, install the ntfy keyring:
sudo mkdir -p /etc/apt/keyrings
sudo curl -L -o /etc/apt/keyrings/ntfy.gpg https://archive.ntfy.sh/apt/keyring.gpg
Add the repository to your apt sources:
echo "deb [signed-by=/etc/apt/keyrings/ntfy.gpg] https://archive.ntfy.sh/apt stable main" \
| sudo tee /etc/apt/sources.list.d/ntfy.list
Finally, update and install:
sudo apt update
sudo apt install ntfy
Packages are built from the official ntfy GitHub repository.