Sounds like you didn't read the logs or try manually loading the module.
Dunno if the latter is even possible in this case.
If you install in expert mode, the Debian installer will ask you whether
you'd like to add contrib and non-free.
In Iceweasel if you goto where ever > addons > get addons, you get to the
Mozilla addons site who also host proprietary addons. Some addons don't
mention any license, some say proprietary.
Debian the distro can be free if you know what you're doing and you're
careful. But it's not something you can recommend to ordinary people if you
care about their freedom. Also, Debian (the project) distributes proprietary
software.
Some related articles
https://www.gnu.org/distros/optionally-free-not-enough.html
https://jxself.org/debian-doubletalk.shtml
