V0 Domain Handshake HNS

I try to setup my domain with namebase.io and always get Invalid Configuration by Vercel.
It shows: “We are attempting to create an SSL certificate for the domain asynchronously.”

I asked the Namecheap Support and they replied:

“SSL cannot be installed and HTTPS protocol is not available”

This seems to be the issue with Vercel, because Vercel says in its config:

“We are attempting to create an SSL certificate for the Domain asynchronosly”.

Several years ago it worked, why it is not now working with Vercel?

I found a Video using SSL in Handshake: https://youtu.be/BH6bRIE5qOI
don’t know how to edit SSL in Vercel. Can you help?

I think I put a custom CDN in front of Vercel like bunny.net to get the certificate.