The lensfundb is inside the appimage.
You can either (1) decompress the appimage and add your file, or (2) point rt at a different lensfun database directory, as detailed here: Apply built-in lens correction for Nikon 24-70 F4 S - #20 by heckflosse
The lensfundb is inside the appimage.
You can either (1) decompress the appimage and add your file, or (2) point rt at a different lensfun database directory, as detailed here: Apply built-in lens correction for Nikon 24-70 F4 S - #20 by heckflosse