How to recover username on Facebook?

Question

Facebook

Hello. Accidentally changed the username on fb from name1 to name2. But it was a mistake and I wanted to come back. But! It says to me that name1 is no longer available. Although about 10 seconds have passed and after clicking on the link with this name, it says that the page was not found. Actually the question is how to get your username back? :)
PS Of course, I knew that Facebook was still that crutch, but I didn’t think that it was so miserable in terms of elementary things...