Flatpak is a Linux program that can be used to install some other Linux programs. If you need a program that's not available on the desktop or through a module, you can look with flatpak to see if it's available.
The software is already installed but no software repositories are so the first step is to add one. The most popular is flathub so let's install it.
flatpak remote-add --user --if-not-exists flathub https://flathub.org/repo/flathub.flatpakrepo
Once installed, you can
flatpak install org.texstudio.TeXstudio flatpak run org.texstudio.TeXstudio
The applications you install with flatpak don't work remotely through the X11 protocol, they can only be used on site in front of the computer.