GoDaddy doesn't support CNAME flattening or dynamic ALIAS records. I suggest you change your domain's nameservers to point to Cloudflare's nameservers. This will allow you to use a CNAME record for the root domain.

You can read more about this here: https://docs.railway.com/networking/domains/working-with-domains#adding-a-root-domain

I think the issue may be with the DNS configuration rather than Railway itself.

From your screenshots, Railway is asking you to create a CNAME for @ (the root domain), but you mentioned you're trying to use api.rutadigitalcrm.com.

A couple of things to check:

Which domain did you actually add in Railway?

If you want api.rutadigitalcrm.com, Railway should normally ask for a CNAME with the name api, not @.

If Railway is showing @, it suggests the root domain (rutadigitalcrm.com) may have been added instead.

Does your GoDaddy zone already have A or AAAA records for @?

A CNAME cannot coexist with A/AAAA records at the same hostname. If @ already has A records, GoDaddy will reject the CNAME.

Could you share:

the domain you added in Railway,

and a screenshot of your current GoDaddy DNS records (A, AAAA, CNAME, and TXT)?

That will help determine whether this is a root-domain conflict or simply the wrong hostname being configured.