Request to create a Github site in the same deleted repository name

I changed my username from NithKosal to kosalnith, and my site moved to https://kosalnith.github.io/nithkosal.github.io. While I’m trying to create a new repository have the name this below, the site still likes ablow. I discuss the deleted account and create this account now I create a new repository but it shows that *The repository nithkosal.github.io has been removed and cannot be reused. *

How I can get it back? Pls, help me with this problem!!!