Intellij - access to system shell

IntelliJ Idea has a nice embedded terminal emulator. However, using flatpak, that terminal only has access to a default shell and to the sandboxed filesystem.

It would be nice if it could use my shell (which happens to be fish), and if it had full access at least to the project directory (but accessing $HOME or the whole filesystem would be better).

Also, git credentials are not available inside the sandbox.That’s another nice-to-have.

I understand the security implications, so ideally it should be an explicit opt-in.