The selected domain cannot be added to an account.

I have a domain name want to point about hosting but can’t point about because when I click Check it full error as the title question so admin let me ask how do I get to be able to point a successful domain? Thank you!

That error means the domain is already in use, is invalid or is blacklisted. If you would like a more specific answer, it would help a lot if you could include your domain name. After all, it’s hard to figure out why you can’t add a particular domain without knowing that domain.