Custom domain not delete

I tried to create a custom domain and it failed. I have a domain account that I tried earlier, and I deleted the site I was distributing at that time. After trying to do it again, it doesn’t work. Help.

my domain:

Hey there! Thanks for reaching out. Are you asking us to delete your custom domain from your site?

If so, please verify domain ownership and let us know by responding here when that’s done. If the verification is successful we can remove the domain from the account so you can try using it again.