Unless you have a particular reason to slow the shutter speed, ND filters have no place in drone still photography.
Slapping a filter on your camera won't fix overexposure.
Making the correct exposure settings is the answer.
If your images are consistently overexposed, check the EV info in the line of camera data near the top of the screen.
If it's showing a + number, dial that back to EV0 or EV -0.3