nameserver is just the name of the place where your files are stored.

The nameservers for WA are

ns1.mywahosting.com
ns2.mywahosting.com

Here's a training on how to do it https://my.wealthyaffiliate.com/training/wa-hosting-setting-up-your-domain-dns/connect-namecheap-domains-with-wa-hosting

And one more just in case

https://my.wealthyaffiliate.com/training/setting-up-wa-hosting-for-your-new-namechep-domain-names

Nameserver*

It's all in the training. I'm pretty sure this is where Kyle shows you how to do it:

https://my.wealthyaffiliate.com/training/how-to-transfer-a-siterubix-website-to-your-own-domain