Welcome to Swiftwave Debian Repository !
Run the following commands to add the repository to your system
sudo mkdir -p /etc/apt/keyrings
sudo mkdir /root/.gnupg
sudo gpg --no-default-keyring --keyring /etc/apt/keyrings/swiftwave.gpg --keyserver keyserver.ubuntu.com --recv-keys DD510C86CD3F6764
echo "deb [signed-by=/etc/apt/keyrings/swiftwave.gpg] http://deb.repo.swiftwave.org/ swiftwave stable" | sudo tee /etc/apt/sources.list.d/swiftwave.list
Then run the following commands to install Swiftwave
sudo apt update
sudo apt install swiftwave