The debian/watch file points to stale ftp:// URL, so I had some
challenge to find the proper upstream source code.  I tracked it down
and found release tarballs here:

https://www.alsa-project.org/files/pub/lib/
alsa-topology-conf-1.2.5.1.tar.bz2

Alternatively upstream git repository here:

https://git.alsa-project.org/?p=alsa-topology-conf.git;a=summary

With mirror here:

https://github.com/alsa-project/alsa-topology-conf

/Simon