Can't add Name Server to ddns -
Following this tutorial
https://www.dynu.com/Resources/Tutorials/DynamicDNS/CreateNSRecord
#Step 1 is fine...
Step 1

Log into control panel, go to Dynamic DNS Service Icon DDNS Services and click on your domain name.

#but there's no option in 'Control Panel' for Name servers
Step 2

Go to DNS Records Icon Name Servers to add an NS Record.
*this doesn't appear

Am I looking in the wrong place?
Thanks!

Do you have your own domain name or are you using Dynu's third-level free hostnames? You can only set up name servers if you use your own registered domain such as yourname.com.