Hello, my question is whether I can install Firefox on my Glitch project. apt install Firefox does not work because I am not root. Is there any other option?
well, you can try building from source. Or using notroot Tutorial: How to install any package from apt-get on Glitch
Sudo isn’t supported by glitch, likley for security or storage reasons, however like @random said, you can find a work around.
Firefox also has a mirrored repo on github, so you could check that out. https://github.com/mozilla/gecko-dev