DomainPeople upgraded their Domain Name Manager, which now doesn’t allow the creation of Name Servers based on your domain name. So you’re required to submit a ticket to create/update your Name Servers based on your Domain Name. I’m so glad I moved to Hexonet, because I have direct access to this.
UPDATE: If you read the comments below, Andrew has pointed out that DomainPeople has added an option for “Register Nameservers” which should then allow you to register nameservers based on your domain.