Hi @hexuhua. It looks like you were using a legacy feature. Vercel doesn't generally allow multi-level *.*.vercel.app subdomains. There is an exception, though not recommended, that lets you add a multi-level subdomain if it matches the team slug. For example, blog.my-awesome-project.vercel.app could not be added, but blog.my-team-slug.vercel.app could.

The better solution is to use a custom domain that you own and control.

Hi @amyegan .Thank you for your reply. I am indeed using my own custom domain right now, but I still need temporary control of the original domain to get my Google Search Console indexed pages migrated to the new custom domain.

I learned from Vercel AI's reply that I can change the Team slug by changing the Team URL. But I was warned that I couldn't change it to hexuhua, and then after several clicks it now warns me Too many requests - try again in 6 days. I thought it was hexuhua being taken, but when I jump to https://vercel.com/hexuhua in my browser URL, it redirects me to my current team page https://vercel.com/hexhs-projects. I don't know how to proceed.

The hexuhua slug is already in use for your account username, so it's not available to use as a team name unless you change your username first.

OK, I've completely figured out the relationship between account user and teams and these slug. So now I just need to wait 6 days and try again to modify the user slug and team slug and then restore the https://blog.hexuhua.vercel.app. Awesome thanks for your help. @amyegan