Preview deployement can not be access through dns record

What is the name of the domain?

robin-protoocol.com

What is the error number?

522

What is the issue you’re encountering

preview deployement can not be access through dns record

preview deployment: develop.robin-web.pages.dev
dns record: CNAME testnet develop.robin-web.pages.dev

not access for testnet.robin-protocol.com