Error: Can't find plugin metadata: org.kde.plasma.eventcalendar

[DimitriBolt]

dimitri@M6800:~/eventcalendar$ sh ./install
./install: 21: [: 0: unexpected operator
./install: 1: desktoptojson: not found
dimitri@M6800:~/eventcalendar$ Error: Can't find plugin metadata: org.kde.plasma.eventcalendar

See screenshot.