I posted this question on the KDE Forum and was advised to ask the same question here:
Can someone tell me how to make my addon available to Dolphin? In Dolphin>Settings>Configure Dolphin>Services>Download New Services takes me to
“Get Hot New Stuff”. When I search for my modified routine for secure-delete https://store.kde.org/p/1295593 it does not appear. I would like to
make it available to others. I have modified Vanbosco’s routine to make it work in KDE Plasma 5.