View the status of the zone

In the control panel go to DNS → Domain Zones.

Look at the status in the zone line.

NOT DELEGATED

NOT DELEGATED	The NS Selectel servers are not specified on the domain registrar's side: `a.ns.selectel.ru`, `b.ns.selectel.ru`, `c.ns.selectel.ru`, `d.ns.selectel.ru`, therefore, resource records are given from the servers of the domain registrar
DELEGATED	Domain resource records management delegated to Selectel servers, resource records are given from Selectel servers

The NS Selectel servers are not specified on the domain registrar's side: a.ns.selectel.ru, b.ns.selectel.ru, c.ns.selectel.ru, d.ns.selectel.ru, therefore, resource records are given from the servers of the domain registrar

DELEGATED Domain resource records management delegated to Selectel servers, resource records are given from Selectel servers