Hello I'm new to KDE. I tried to add a widget inside a panel and I can't type into it (webslice with a webview in it and the default clipboard). I tried both latte panel (ver 0.10) and plasma default panel. Mouse click is ok but for input the widget does not get focus. Is this an issue or am I missing something? If the widget is expandable ie a clipboard icon, click on it and type on the popup everything works ok but if the widget is the actual popup component it can't get focus.

I don't know the widget you are talking about (never used it), but not all widgets are meant for use in a panel, and just by looking at the widget in question this seems to be the typical Desktop widget.

Since this is a third-party provided widget you should ask the author of it.