MachineName vs IP in URL

Hi! I'm guessing this is a pretty simple fix, but I'm very new to NGINX. I'm having an issue where if I use the url:

http://myservername.mydomain:8080/

All is good. However, if I use:

http://1.2.3.4:8080/

I get the default 404 from NGINX. What must I do to make both work?

Thanks,
Eric