How to scroll in GUI with keyboard?

When starting Octave from the bash prompt, it is easy to scroll up and down with the keyboard, using Ctrl+Shift+Up/Down/Home/End/PgUp/PgDn. But in the GUI there does not seem to be any keyboard shortcut listed. Is there a cheat code to scroll back and forth without using the mouse? Running Octave 7 on Arch Linux.