On Sun, Feb 20, 2022 at 10:33 AM Paolo Dongilli <dongilli@fuss.bz.it> wrote:

> The following packages have unmet dependencies:
>  openboard : Depends: libfdk-aac1 (>= 0.1.6) but it is not installable
> E: Unable to correct problems, you have held broken packages.

Clear. You also need the non-free  repository of Debian activated in your sources.list because the library
libfdk-aac1 is there.

Indeed, adding non-free fixed the problem.
However I hope that you are considering this a workaround, not a solution, because the installation script (`fuss-client`) should do this automatically, if needed.
 

# apt policy libfdk-aac1
libfdk-aac1:
  Installato: 0.1.6-1
  Candidato:  0.1.6-1
  Tabella versione:
*** 0.1.6-1 500
        500 http://deb.debian.org/debian buster/non-free amd64 Packages
        100 /var/lib/dpkg/status