Setting up custom email

Glad to see Apple is allowing the use of custom domains with email. I've had a gmail subscription through Squarespace for my business but only use the email and none of the other business tools I pay Gmail for so I'd like to switch the email account over to iCloud.

I'm trying to set up the DNS settings for my domain through Squarespace's website. The MX and TXT records were accepted but CNAME "points to" is getting the flag: Not a valid host name.

Not super familiar with the deep dive in technobabble so I'm not exactly sure what I'm doing (wrong) or how to fix it. TIA!