How to connect a headphone jack to this lm386
On the connectors that you've pasted, they're probably 5 pinned for other reason, which may be for a better holding to PCB. Not all pins are always functional only for signals or voltage/current transmit.



On the other side, this module is for mono output only. It means, you can only listen to either left either right speaker.

How to connect? See on picture, but for connector, measure pins for sure!