Invalid domain .ru

It does not matter which domain I enter, I get the result, invalid domain. what is going wrong?

.ru is not a supported domain

And how long?

in the past month added, everything worked

Sorry, I am a bit confused. Do you have it already set up on Cloudflare and are unable to connect, are you trying to set up using Cloudflare name servers or are you trying to register that domain on Cloudflare.

trying to register that domain on Cloudflare

You won’t be able to, as it is not in the list of supported TLDs. As for a timeline on when you can, that is a question for Cloudflare support to answer.

Thank you very much