Run KDE applet from command line (within i3wm)

After a thorough study on KDE5 API, I found the answer to my own question. To start kicker (Application Menu) form within a command line WITHOUT starting the whole KDE desktop, simply run:

plasmawindowed org.kde.plasma.kicker

We can also run a lot of other plasmoids. To see a list of all plasmoids installed, run both of the following:

kpackagetool5 --list --type Plasma/Applet -g  # system wide
kpackagetool5 --list --type Plasma/Applet     # current user

Here is the API page: https://techbase.kde.org/Development/Tutorials/Plasma5/QML2/GettingStarted

Here is a more complete API page: https://techbase.kde.org/KDE_System_Administration/PlasmaDesktopScripting