So i have added my website to Fly.io and everything works but when i go to set the CNAME i
get an error saying name need to be set, what should i put there?
That field is for the subdomain of your domain that you want to point at Glitch. If you want to point your bare domain (called the apex domain, instead of, say, www.mythical-bots.ml) on Freenom, you instead need an A record pointed at the IP address for your *.shw.io domain. You can read more about this here.