They're not going to export data from old (betnomi.bet) to new (betnomi.com), therefore we need to create a new account to their new platform if we wish to continue playing on their site.
It is not a question to create a new account that is easy.
This is for users who have accounts on Betnomi.bet and still have funds there. The owner mentioned about the account retrieving process from the betnomi.net to the new domain name.
I think if you don't want to create a new account, you can choose the account retrieving process but the new domain is just in beta version.
I also have an account on betnomi.bet, I think the retrieval that he was saying is if you have funds left on there old site to withdraw. I also asked this on their chat support on betnomi.bet, we need to create a new account to their new website because they are not going to export the data from old to new.