According to section 2.2 of the manual, you can use the Escape key pressed twice in place of the CTRL key. This allowed me to use Nano's key combination for GO TO LINE when running Nano on a Jupyter/ JupyterHub and accessing through my browser. The normal key combination was getting 'swallowed' as the manual warns about can more often happen with the ALT key on some systems, and which can be replaced by one press of the ESCAPE key.
So for jump to line it was ESCAPE pressed twice, followed by shift key + dash key.