I need to create an own nameserver for my domain proiecto.com (ns1.proiecto.com, ns2.proiecto.com, etc) but the option "NS-Name Server" does not appear in the list of types in "DNS Records" -> "Type"

See: How to add an NS record? here: https://www.dynu.com/Resources/Tutorials/DynamicDNS/CreateNSRecord


HELPPPPP

You can chnage the name server records in the 'Name Servers' section instead of 'DNS Records' section. You also need to add the following A records in the 'DNS Records' section:

ns1.proiecto.com ->199.233.237.18
ns2.proiecto.com ->207.38.70.53
ns3.proiecto.com ->199.241.29.200
ns4.proiecto.com ->45.76.81.250
ns5.proiecto.com ->192.249.63.60
ns6.proiecto.com ->173.255.227.222

The last step would be to add the above glue records at your current registrar and list ns1.proiecto.com to ns2.proiecto.com as name server records at the registrar.