How do you use the Set Property block if your components hadn`t be created?

The extension I use is Dynamic Components Extension by yusufcihan
my code looks like this

Screenshot from 2022-12-14 19-05-22

I tried to log the user's visited websites so I can make the browsing history by using buttons. But I think, how do I edit the component`s property, if its not already exist?

why set property if it not exist ?