How to set the preview of a plasmoid widget to a png

[luisbocanegra]

That is currently not possible, the Icon property expects a name of an icon in the icon theme:

Icon is the icon name associated with the widget. You can search for icon names in the /usr/share/icons folder.

Source: https://develop.kde.org/docs/plasma/widget/setup/#metadatajson

@luisbocanegra

Setting a custom path in the widget metadata.json is currently not possible, here is the feature request for that: https://bugs.kde.org/show_bug.cgi?id=509896

So while you can ship a custom icon and display it when the widget is added to the panel/desktop (using Kirigami.Icon), other places like the widget explorer or the widget about page need an icon that is on the icon theme.