No matter if the camera filter has broken, or you just want a spare lying around in case it does break, you might find this useful.
From Amazon
PolarPro - DJI Mini 3 Pro - SHUTTER - ND8 + ND16 + ND32 (3-Pack) - Ultra-lightweight aluminum - Precisely engineered - horizontal and vertical shooting modes - Color neutrality
Scan
Polar Pro DJI Mini 3 Pro Shutter Collection Filters
Clifton Cameras
Polar Pro Mavic Mini 3 Pro - Shutter Collection