A:Answer Yes, you can attach a external microphone to the Osmo Action Camera but with an external microphone adapter. . However, you must remove the Memory Card/Power Adapter door, which will make the camera non-waterproof.
The adapter plugs into the USB-C power port and breaks it out into a 3.5mm microphone port/USB-C power port.
CYNOVA Osmo Action Dual 3.5mm Mic Adapter - Made for Osmo Action with Authorization