Courtesy accidental plugin (v3)

Hi! Anyone knows why this wonderful plugin does not work in version 3?

https://musescore.org/en/project/add-and-remove-courtesy-accidentals

Inside the plugin .rar appears the folder named v3, so I understand, it should work. I put the plugin in the plugin directory, and I can add it from the plugin manager menu inside the MuseScore 3. But when I try to use it - nothing happens..

Any alternative? (not manual, please) ;)