Moving to old-ish apartment, how do I install the lights here?

I know how to install the newer type where you just have to basically plug it in.

I also have an idea how to install for the second pic, I’m thinking maybe I just need to buy adapter ( same as second pic) to install on the first pic, but i don’t know what it’s called in finnish and don’t know where to buy, as ikea adapters tend to be the newer type(we have ikea light fixtures). Any tips what to buy as an adapter for these? What are they called and where to buy it?