Swach for Linux
Here you can find various options for installing Swach on Linux. Swach is built natively for Ubuntu/Debian, and support for various other Linux distributions is added via Snapcraft. If your distribution supports Snapcraft, you should be able to use Swach.
Install on Ubuntu
Go to Swach in Ubuntu Software and click install. If the link doesn’t work, open Ubuntu Software and search for Swach.
Install via command line
snap install swach
If you run another Linux distribution than Ubuntu, first see https://snapcraft.io/ for how to install snap, then run the command above.
You can manually download the latest debian build here.