You can register .ro domains and every Romanian extension (.com.ro, .info.ro, .org.ro, .store.ro and more), plus international ones such as .com, .net, .org, .e...
Add the TXT record to the DNS zone managed by the provider your domain’s nameservers point to. This is not necessarily the provider where you registered the domain. First check the active nameservers, then open DNS management with the relevant provider.
Copy the record name and value exactly as requested, bearing in mind that some interfaces automatically append your domain name. Do not delete existing TXT records: they may be needed for email or other verification processes. Once saved, the change may take time to become visible. Then try verification again in the service that requested the record.