How to add plasmoids to kde iso

I am making my own manjaro kde “distro” for personal use. I am following the steps on the wiki, but I cant seem to find where or how I should add the plasma extensions that I want to be present in the iso once it is completed.
how can i do that?

The extensions are all in the official repository?

Ok thanks. I will try it as soon as can I can. I will let know the results

I cant find them. I want to add “tiled menu”, weather widget by clearmartin, better inline clock and a few others to my iso, buy I dont know how or where to find the packages