How to use `qdbus` or `systemsettings` to change the `kcm_virtualkeyboard` cfg in the terminal?

I use kde6.

I can use systemsettings kcm_virtualkeyboard to open the kcm_virtualkeyboard setting in a window, but --args 'foo_IME' seems to fail (Maybe this is not supported).

In qdbus on my installed kde6, it shows only ‘org.gtk.Settings’ which has the term ‘setting’. But it seems to only have something like qdbus org.gtk.Settings /modules/keyboard org.kde.KeyboardLayouts.setLayout but not one method to choose the virtualkeyboard.

This feature will be helpful when I want to use one script to automatically change the kcm_virtualkeyboard when in one specific context.

Q:

Is there one command to use qdbus or systemsettings to change the kcm_virtualkeyboard cfg in the terminal?