Yes, You do that where you had gotten your Domain and find the NS records. It can’t be done here on this hosting. DNS NS tags are only Domain Host specific. Domain setting are different and Hosting (Like Infinity Free) are different.
You can’t change the nameservers on free subdomains. So you can just ignore the warning (not error - this message is yellow, not red) and set your CNAME records through our panel.
Thanks. I can leave the name servers as they are. All I need now is the SSL Certificate from Gogetssl. This was requested 3 days ago, but has not come. It still shows: