Mapping GCP App Engine to a subdomain (not naked domain)

Question

I want to map a subdomain xxxx.domain.com to an App Engine project, I verified my ownership of the domain name (naked name) domain.com registred in GANDI via TXT.

After the verification, I only added xxxx.domain.com in the scope of domain names and I got this informations as result :

I'm confused what records to add to xxxx.domain.com and which records to add to domain.com to make the subdomain working.

By the way, I have domain.com pointing to another service and I want to keep it working

Many thanks

Answer 1

For a subdomain, you just need to add one DNS record:

Name: xxxx (this is your subdomain)
Type: CNAME
Data: ghs.googlehosted.com

The A/AAAA records are only needed for a naked domain and since you aren't using the naked domain with GAE, you can skip that.