.tk website

Hi I was doing research and came across some sites like this :https://hook.icbosdalalano.tk/ What are these .tk sites and is there a tool to make them? I notcied they were indexed by google

Today i opened freenom and also dot.tk website, i searched for free domain. When i click on get now it shows that it is not available. I tried for paid domain it also is not working. Can anyone check once for me?