Freedombox Can't Install Any Apps

I am a new Freedombox user with no web dev experience or any technical experience with computers, so I apologize if my problem description is not detailed enough.

Problem Description
Whenever I try to install an app, I receive this error prompt:

I have tried installing Matrix, OpenVPN, and Calibre and all generate this error.

I am on Windows 11, so might this be a problem?

I connected to Freedombox via SSH and ran $ sudo apt upgrade-all in an attempt to fix it. It did update my freedombox to the latest version I believe, but it did not fix the error problem.

Debian GNU/Linux 11 (bullseye) and FreedomBox version 21.4.4
Windows 11 Home Version 21H2, Intel(R) Core™ i7-10700K CPU @ 3.80GHz 3.80 GHz
Bought pre-installed hardware, followed Olimex instructions

Read through this thread and this thread.. It sounds like you need to update /etc/apt/sources.list. I’m not sure if there’s a simpler way for you to do that besides running an editor (e.g., vi) from a terminal prompt in Cockpit, which might feel a bit hairy if you haven’t done something like that before. In that second thread, you’ll find the suggestion “For any other non-techies following a long, I found this article helpful in working out how to edit the file”.

I actually flashed my SD card and did a fresh install just to get used to the process. Things are installing now, so this can be closed. I’m sorry for wasting anyones time!