It’s always advisable to update your DNS or Domain Nameservers to make sure that they are pointing to the server or hosting account youwant to use the domain name on before adding the domain name. However, if you missed that step, the system will advice you with a notification during the domain adding process to go and point or update the domain in question’s namservers to point to the current server or hosting account.
If you want to migrate your website without a downtime, in this case you don’t have to update the nameservers until you finish the migration and then update the latter to your preference, because when you update namservers they take sometime to fully propagate on the internet.
As always, if you don’t know how to do this and need assistance, don’t hesitate to submit a ticket or contact our support team.