/usr/share/plasma/plasmoids/ is in milou 4:5.12.4-0ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/plasma/plasmoids/org.kde.milou/
/usr/share/plasma/plasmoids/org.kde.milou/contents/
/usr/share/plasma/plasmoids/org.kde.milou/contents/code/
/usr/share/plasma/plasmoids/org.kde.milou/contents/code/globals.js
/usr/share/plasma/plasmoids/org.kde.milou/contents/ui/
/usr/share/plasma/plasmoids/org.kde.milou/contents/ui/SearchField.qml
/usr/share/plasma/plasmoids/org.kde.milou/contents/ui/main.qml
/usr/share/plasma/plasmoids/org.kde.milou/contents/ui/previews/
/usr/share/plasma/plasmoids/org.kde.milou/contents/ui/previews/Audio.qml
/usr/share/plasma/plasmoids/org.kde.milou/contents/ui/previews/TextPreview.qml
/usr/share/plasma/plasmoids/org.kde.milou/metadata.desktop
/usr/share/plasma/plasmoids/org.kde.milou/metadata.json