Hi Forum, I'm using my Canon Legria HF G26 with external Zoom H6 via mic in. The sound from the external mic doesnt appear on/in the film / is this a setting? yours B
Have you adjusted the levels - also what port are you sending out from the H6, may have to up the gain setting. (not 100% familiar with the H6 line as prefer something with less self-noise).
Not familiar with Legria Menus, but in the cameras you can select 'Sound recording' in the shooting menu, and change to manual and boost there. For the H6 - there should be an option in the settings to boost gain from the line-out. Alternatively, have you tried feeding the audio out of the headphones from the H6 to the Legria HF G26? - more of a quick fix, but you might at least get some audio out of it. However I would dive in to the manual for your F6 and see what you can do to boost the signal.
Also look at the manual on the Canon site for the G26 - should be on page 70 how to switch it to an external mic input.