How to find my website name server

[blin]

Q: We have some DNS issues and can' access the website or ping it. The nslookup shows the DNS server can't find owa.chicagobotanic.org: Non-existent domain. I think it could be the name server issue, but, how can we find out which name server.

A: You just need to search whois online. The whois information should give you the name server information. Or contact your website hosting company.