(GitHub, Adobe Exchange, or the photographerstoolbox.com archive) will never ask for a serial key.
: The plugin is "free" to try, but the trial version restricts you to exporting 10 images at a time Receiving the Code lr mogrify 2 serial number
Once registered, you can use the following features for unlimited batch exports: Photographer's toolbox LR/Mogrify uncheck? - Adobe Community (GitHub, Adobe Exchange, or the photographerstoolbox