redirect is only possible to ip adress by dns hosting settings

I needed to bind hosting/vps IP to domain on domain provider side. Tutorials say I need to copy those lines and enter on domain provider website somewhere.

ns1.digitalocean.com.
ns2.digitalocean.com.
ns3.digitalocean.com.

I open my domain provider settings. There are default NS servers

nsb4.srv53.com nsb3.srv53.com .....

, which are told not be touched and that all settings must be done on other website here https://dnshosting.org/

At this website opposite to my domain in my account there only the following options

1. Default parking page(wrong for sure)
2. Redirect through frames (not our case)
3. Custom parking page(wrong also)
4. Switch off redirect(><)
5. Direct redirect (what I need)

But redirect is only possible to ip adress, not ns2.digitalocean.com. which means that ip adress will be shown in url, not domain - so I guess that's all wrong.

Help, please. Any ideas how to handle this?