I'm using a version of Gnome called Nautilus 2.28.4 at a library.
Last night using my phone, I successfully rooted my LGOG E971 but what happened is I installed TWRP and got this error message:
Secure Booting Error
Cause Boot Certification verify
So now all morning I've been trying to install Heimdall. Problem is I believe the library has disabled any access to the Terminal.
On that note, I have zero knowledge of Gnome/Fedora/Ubuntu to begin with.